Banging sounds heard during Titan search, according to internal government memo(cnn.com)
cnn.com
Banging sounds heard during Titan search, according to internal government memo
https://www.cnn.com/2023/06/20/us/titanic-shipwreck-vessel-missing-tuesday/index.html
106 comments
Being in an enclosed space, knowing no one else can hear you, surrounded by people probably having a panic attack, at the bottom of the ocean in total darkness while you are slowly noticing the air getting harder and harder to breathe… yeah I would’ve taken the hull imploding over 80-something hours of that.
One guy is down there with his 19yo son… empathy is a powerful thing, imagining that situation just makes my heart sink.
One guy is down there with his 19yo son… empathy is a powerful thing, imagining that situation just makes my heart sink.
> Being in an enclosed space, knowing no one else can hear you, surrounded by people probably having a panic attack, at the bottom of the ocean in total darkness while you are slowly noticing the air getting harder and harder to breathe…
I had an old guy tell me about why he was claustrophobic once. Closed doors and the dark were a challenge.
He got depth charged in a submarine during WWII. The lights got blown out, water was coming in etc.
Everyone survived but it had a marked effect on him.
I had an old guy tell me about why he was claustrophobic once. Closed doors and the dark were a challenge.
He got depth charged in a submarine during WWII. The lights got blown out, water was coming in etc.
Everyone survived but it had a marked effect on him.
That's an incredible story. Someone had to keep their wits about them to successfully resurface. I imagine there was a lot of experience and training that saved that crew.
They have another ~30 hours of air.
The biggest hope is that they are not terribly deep trapped near the surface and can be located in that time.
The biggest hope is that they are not terribly deep trapped near the surface and can be located in that time.
How could they be trapped "near" the surface? That would require the sub to maintain buoyancy precisely, which seems unlikely without active systems.
As I understand it, the vessel is not able to surface on its own. At its most buoyant, a small amount of the sub will emerge from the water, and that weight will push it back down, so the vast majority of the sub is underwater. This bobbing, which depending on waves can have a small amount or none of the sub above water at any time, would make them hard to detect but easy to retrieve if they were located.
Imagine being so close yet still not able to escape the vessel. I don't know what is standard for subs, but it strikes me as particularly terrifying that they have no way to open it from the inside.
I think, but based on nothing but news stories about this incident, that's common for very deep sea submersibles. It makes sense, the could opt out of a whole bunch of surface ship concerns and they expect to be launched and retrieved. It also helps simplify the design if you don't have to worry about opening hatches from the inside. That adds complexity and can introduce new failure modes.
I'm betting that little potty bucket may be filling up...
I don't see why that would make them hard to detect. As long as you're above the waves a few percent of the time you should have no trouble getting a signal out, and if you have an antenna you could probably get GPS too, plus, there's some pretty powerful dyes you could release periodically, LEDs that could be seen easily if it's just a few meters of water....
Seems like it would have to be criminally bad design without any kind of signalling at all, to be near the surface and not found within hours.
Seems like it would have to be criminally bad design without any kind of signalling at all, to be near the surface and not found within hours.
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Air is great and all, but hypothermia will get them first.
And do they have water to drink?
They had 4 days of air
When they launched. At $250k, they probably had some drinks on board for a 24 hour trip, and 3 days of no water is considered survivable. So air is most likely the limiting factor, but it's possible they messed up the drink provisions extremely badly.
Carbon dioxide levels will do them in before lack of oxygen.
Assuming they don't have filters onboard, yeah. I thought it was possible to filter out many man-days of CO2 with relatively small filters.
In a well-designed submersible that goes through thorough testing and gets a classification and rating... which I gather the CEO took short-cuts on. He's one of the passengers on board.
Much more if cannibalism set in.
they'll be out of air or hypothermic long before they get crazy enough to start eating each other or drinking blood
Isn't it just a relatively doable matter, of hooking up a wire by a robot and pulling out to the surface, assuming a suitable robot can be flown and deployed soon enough?
It's ~12,500ft (~3,800m) down on the seabed at this point, most likely. Nothing is "relatively doable" at these depths and associated conditions.
According to Wikipedia
> The vessel was expected to resurface at 18:10 ADT.[16] Authorities were notified about the incident at 18:35 ADT.
https://en.m.wikipedia.org/wiki/2023_Titan_submersible_incid...
One could argue that the delay once communications were lost is reasonable until the sub was overdue back.
> The vessel was expected to resurface at 18:10 ADT.[16] Authorities were notified about the incident at 18:35 ADT.
https://en.m.wikipedia.org/wiki/2023_Titan_submersible_incid...
One could argue that the delay once communications were lost is reasonable until the sub was overdue back.
I don't think anyone can actually take the company to court, the passengers signed their lives away (pardon the pun), to be able to take that ride to the Titanic.
I would be curious to know if it had a backup propulsion system in case the primary failed?
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This makes me think of the search for the USS Thresher, a US Navy submarine. After the sub sank, the Seawolf was one of the Navy ships that went looking for it. Sonar operators on the Seawolf heard what they thought were manually operated SOS signals, banging of metal on metal, and eventually something resembling a voice. While these reports have started some conspiracy theories, the sonar readings from the initial sinking and wreckage indicates the Thresher imploded near instantly at depth, which would be unsurvivable for any amount of time.
Honestly the chance of anyone being alive in the Titan is about as close to zero as you get; these rescuers want so badly to save them that they're hearing what they want to.
I hope I'm wrong though.
https://m.soundcloud.com/user-798629330/episode-261-the-uss-...
https://youtu.be/4dka29FSZac
Honestly the chance of anyone being alive in the Titan is about as close to zero as you get; these rescuers want so badly to save them that they're hearing what they want to.
I hope I'm wrong though.
https://m.soundcloud.com/user-798629330/episode-261-the-uss-...
https://youtu.be/4dka29FSZac
The last section of this article "Update, July 15" addresses those points about the Thresher tragedy: https://www.thedrive.com/the-war-zone/41523/uss-threshers-cr...
What is it about this type of story that is so attention grabbing? Kids trapped in cave, Plane missing in jungle, etc etc. Is there a name for this?
Pragmatically speaking, this is of little consequence to most people, there are greater human tragedies going on, there are more catastrophic engineering failures happening, more egregious negligence,.. something about the unknown element of it.
Pragmatically speaking, this is of little consequence to most people, there are greater human tragedies going on, there are more catastrophic engineering failures happening, more egregious negligence,.. something about the unknown element of it.
They are outliers.
Most tragedies the people are dead, outcome is known.
These situations usually have these things in common:
1. Very unusual situation
2. Race against the clock
3. Remote location
4. Extreme measures needed for rescue that may have never been done
5. May still die even if found
Most tragedies the people are dead, outcome is known.
These situations usually have these things in common:
1. Very unusual situation
2. Race against the clock
3. Remote location
4. Extreme measures needed for rescue that may have never been done
5. May still die even if found
>What is it about this type of story that is so attention grabbing?
In this particular story: Those guys are pioneers, they are doing something almost nobody has done before, like going deep down 4 kilometres under the surface of the ocean.
This takes guts. And people admire those that have the guts. It is primal instinct, as the people that take risks and survive usually makes the tribe or society improve.
Things that are routine today like planes flying without crashing down or reusable rockets or going to the moon were at some time extremely risky.
In this particular story: Those guys are pioneers, they are doing something almost nobody has done before, like going deep down 4 kilometres under the surface of the ocean.
This takes guts. And people admire those that have the guts. It is primal instinct, as the people that take risks and survive usually makes the tribe or society improve.
Things that are routine today like planes flying without crashing down or reusable rockets or going to the moon were at some time extremely risky.
> Those guys are pioneers, they are doing something almost nobody has done before, like going deep down 4 kilometres under the surface of the ocean.
They are rich tourists going down to look at a famous shipwreck, the same as hundreds of actual professionals have done. Much like the rich tourists who are mostly carried up Everest this does not take guts or ability, it takes a fat wallet and nothing more. Actually, it probably takes more ego than intelligence if you get into the craft they took down now that we have learned more about its potential safety flaws.
The nature of the event is why we are paying attention. The people trapped and how it happened is icing on the cake, but we would all still be watching if it was the Alvin submersible and some university researchers inside. To be honest we would probably care more if it was actual professionals who were at risk doing work to expand human knowledge instead of a tourist day-trip; I certainly would actually care about the outcome in that case, while I can't be bothered to care one way or the other if this particular group of tourists lives or dies.
They are rich tourists going down to look at a famous shipwreck, the same as hundreds of actual professionals have done. Much like the rich tourists who are mostly carried up Everest this does not take guts or ability, it takes a fat wallet and nothing more. Actually, it probably takes more ego than intelligence if you get into the craft they took down now that we have learned more about its potential safety flaws.
The nature of the event is why we are paying attention. The people trapped and how it happened is icing on the cake, but we would all still be watching if it was the Alvin submersible and some university researchers inside. To be honest we would probably care more if it was actual professionals who were at risk doing work to expand human knowledge instead of a tourist day-trip; I certainly would actually care about the outcome in that case, while I can't be bothered to care one way or the other if this particular group of tourists lives or dies.
*Some of them are rich tourists. Paul-Henri Nargeolet is one of the people on board, has done more than 30 dives to the site since the 1980s, technically owns the rights to the ship, was in the French Navy for 20+ years, and has recovered artifacts from the site - only person to do so.
Not quite fair to call him a tourist.
Not quite fair to call him a tourist.
Taxi driver in that case? Someone paid to take rich people around...
He also has a net worth of 1.5 billion dollars.
You can be both rich and the foremost world expert on the Titanic at the same time.
You can be both rich and the foremost world expert on the Titanic at the same time.
I would think he would be sending Morse code, being a Navy man.
I was wondering about that. This banging the rescue teams have been picking up, can sonar or whatever they're using pick it up clearly enough to decode a message? Would they even know what to send?
I think it's the possibility they are still alive and trapped, and might die like there after multiple days of multiple kinds of suffering.
Plus, being unable to call for help is not something we are used to. To me, just BEING somewhere where I could not contact anyone and nobody could get to me in an emergency sounds terrifying even if nothing was actively happening.
Plus, to laymen it seems like the tech to prevent it should be absolutely trivial in the age of satellites. If I was lost somewhere all because I didn't have a $200 beacon device I would be horrified, and these people paid $250k. I'd expect multiple redundant forms of communication, immediately surfacing with a refund if there was any sign of trouble, etc.
Plus, being unable to call for help is not something we are used to. To me, just BEING somewhere where I could not contact anyone and nobody could get to me in an emergency sounds terrifying even if nothing was actively happening.
Plus, to laymen it seems like the tech to prevent it should be absolutely trivial in the age of satellites. If I was lost somewhere all because I didn't have a $200 beacon device I would be horrified, and these people paid $250k. I'd expect multiple redundant forms of communication, immediately surfacing with a refund if there was any sign of trouble, etc.
Isn't that like basic story telling? Someone goes on an adventure, then a catastrophe happens and now we are at the most thrilling part: will they make it out alive? And this is a real story, playing out in real time.
I think a lot of it is schadenfreude. A bunch of rich people pay out their ass to get in a jerryrigged submarine to look at a sunken boat and end up becoming one.
Interpretation is a form of introspection.
For me, it's a lot of things. A metaphor for the mating habits of spiders. A reminder to be thankful for what I have. Just something grisly to contemplate.
For me, it's a lot of things. A metaphor for the mating habits of spiders. A reminder to be thankful for what I have. Just something grisly to contemplate.
You pretty much nailed it!
In this case, it's because everyone on board was filthy rich.
If it were me or you, we'd be sleeping with the fishes without mention.
If it were me or you, we'd be sleeping with the fishes without mention.
The parent comment already made the connection to the thai kids cave, whose story went around the world. So this part does not play a role about the sensationalism of the story. About the magnitude of the search and rescue effort.. It might do
well sure, that was kids. We only remember that kids were trapped, barely if at all the adults involved.
If that cave was just full of random divers, we'd probably not heard of that one either.
If that cave was just full of random divers, we'd probably not heard of that one either.
And the Chilean miners trapped for a couple of months back in 2010? The fact that all I need to do to remind you of the event is mention 'Chilean miners' should be sufficient evidence to prove an exception to your proposed rule.
I agree with your points. But just imagine the news cycle if the Chilean miners _were_ children!
I'll half concede, fair point.
It was a lot of people (more than 30), and IMO wasn't covered as heavily as say, the Thai cave or this may be.
There is definitely a disaster angle news latch onto, but it's pretty rare for a group of adults this small. There are small plane crashes with more fatalities multiple times a year...
And it can't be the 'missing people' angle, there are like 400k kids every year reported missing with less than milk carton coverage...
It was a lot of people (more than 30), and IMO wasn't covered as heavily as say, the Thai cave or this may be.
There is definitely a disaster angle news latch onto, but it's pretty rare for a group of adults this small. There are small plane crashes with more fatalities multiple times a year...
And it can't be the 'missing people' angle, there are like 400k kids every year reported missing with less than milk carton coverage...
The urgency tickles our savior complex. The situation makes us feel that we might be able to save those souls if only we could figure out the correct bash one-liner to solve it, and that grabs our collective attention.
this seems so weird to me since the majority of the planet isn’t doing anything to save these people.
None of Chillean miners were filthy rich.
Everyone loves a good search and rescue. Is there a better search and rescue right now?
it's relatable. most people have a vivid fear of being trapped somewhere. then empathy kicks in. it's not abstract.
Overt misdirection?
Brown noise?
Brown noise?
I wonder why the submersible was not equipped with redundant "self surface" systems. I imagine the overall density of this submersible to be close to that of water. Such that dropping some amount of ballast (like the metallic rails underneath) may lighten it enough to self-surface. In addition, some emergency "baloons" may be fitted, inflatable in an emergency by CO2 capsules to resurface. And an emergency system to open the sub (e.g. by blowing up a hole somewhere convenient) could be added as well to allow exit once at surface.
It is. It has electromagnetic drop weights that are meant to detach on power failure.
Thing is, when it’s out of the water and the power is off, there’s going to be a mechanism, bolts or dogs or zip ties or whatever, to keep them on - and someone has to remember to detach those as part of the launch.
Thing is, when it’s out of the water and the power is off, there’s going to be a mechanism, bolts or dogs or zip ties or whatever, to keep them on - and someone has to remember to detach those as part of the launch.
It'll be another appaling surprise if they didnt have a panel or box along a checklist, either inside the sub or next to a control panel to store and verify all those safety pins and locks.
It wouldn’t be the first time they’ve had a mundane mistake that has potential severe ramifications - like fitting a thruster backwards. Doesn’t inspire confidence.
I mean - I can think of so many examples in my life where I’ve seen some safety measure Macgyvered out of existence because it was inconvenient, and familiarity breeds complacency. I’m reminded of some really gnarly ski lift accidents where emergency brakes were disabled because they tripped inappropriately due to improper maintenance, and flights which have taken off with their pitot tubes still covered, and inertial measurement units fitted upside down in rockets, and on and on it goes.
I mean - I can think of so many examples in my life where I’ve seen some safety measure Macgyvered out of existence because it was inconvenient, and familiarity breeds complacency. I’m reminded of some really gnarly ski lift accidents where emergency brakes were disabled because they tripped inappropriately due to improper maintenance, and flights which have taken off with their pitot tubes still covered, and inertial measurement units fitted upside down in rockets, and on and on it goes.
The Risks Digest. Highly recommended.
https://catless.ncl.ac.uk/risks/
Endless food for thought.
https://catless.ncl.ac.uk/risks/
Endless food for thought.
Oh, or watertight compartments which didn’t go all the way up the hull because it was expensive and inconvenient. Oh, the irony.
Here is a nice article:
>The maker of the lost Titan submersible previously complained about strict passenger-vessel regulations, saying the industry was 'obscenely safe'
https://www.insider.com/titan-submarine-ceo-complained-about...
>The maker of the lost Titan submersible previously complained about strict passenger-vessel regulations, saying the industry was 'obscenely safe'
https://www.insider.com/titan-submarine-ceo-complained-about...
In acynical way, it is fitting. Titanic was not the worst marine desaster in term of life lost. But since it was the rich and the celebrities who died on tha Titanic, well, it was enough to tackle safety.
When safety issues cause the loss of life, but don't for some reason grab the headlines in specific ways, nobody cares.
When safety issues cause the loss of life, but don't for some reason grab the headlines in specific ways, nobody cares.
Not sure whether it’s applicable here. But when learning scuba diving, we were taught (or rather reminded of, from middle school physics) that a balloon would become bigger as one gets closer to the surface. A balloon 90m under water will be 10X the size when it’s at surface. Therefore, using a balloon for emergency surfacing will lead to a monotonically increasing acceleration rate (which means you’ll going be too fast), or probably bursting the balloon half way through.
Indeed the pressure is huge down there, and this may represent a challange in inflating the ballon in the first place. Looking up the numbers, it seems the pressure at the Titanic is about 400bar, while the pressure of a CO2 cartdrige is about 800bar, so that works.
About the baloon becoming larger as it surfaces, a pressure release valve that vents the baloon based on the pressure differential with the exterior (water) may do the trick.
About the baloon becoming larger as it surfaces, a pressure release valve that vents the baloon based on the pressure differential with the exterior (water) may do the trick.
Use a bell shaped contraption instead of a balloon.
More details about the sub's life support and surfacing systems from a CBS reporter who was on an expedition: https://www.youtube.com/watch?v=jyt7H2tF76w
If they are indeed banging they should use morse code to communicate something
Interesting idea, I actually can't think of anything they are able to communicate that would aid in their rescue. They could probably signal if they are close to the surface, they won't be able to provide much more information on their exact location I think.
Identifying themselves to disambiguate from other random noises?
The banging noise is already treated as non-random but that doesn't make it easy to locate, and they are presumably unable to locate themselves so won't be able to transmit any location details even if you gave them a few words worth of bandwidth, the best they might convey is how deep they are currently are "We are only a few meters above the wreck". for example
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...---... ?
I have a dumb idea; how hard is it to add a location tracker to these kind of subs? Does the high pressure make this incredibly hard to add?
Its not the pressure, but the fact water blocks radio waves. Submarines can’t get GPS signals or transmit their location. Submarines have to rely on other means such as IMUs to track their own location.
What about a signal flare that floats to the surface?
I believe at a certain depth some things compress, density increases, buoyancy becomes negative - and they sink.
They have locator beacons size of a thermos (that ping powerfully using particular frequencies) which they fit on flights etc... i believe some can be received a couple miles+ down in good conditions like are seeing now.
But clearly not everything sinks, or the sub would never be able to surface. If it's just a matter of engineering work, that's kind of literally their job.
The most frustrating is reading somewhere, I can't remember, that there was some discussion about beacons after having lost comms during an excursion in the past. The conversation apparently didn't get there.
My first proper job in my career was IT for a maritime navigation company. This must have been around 2000, and we were selling these to normal people that have boats. I can't believe they did not integrate EPIRB into something like this triggered by an emergency trigger within the vehicle: https://en.wikipedia.org/wiki/Emergency_position-indicating_...
The facts that even if the unclear "7 ways" to surface in case of emergency, that a) the ship doesn't know where the submersible is located, which GPS would easily solve for and b) if it does manage to use one of these seven ways there's no way to exit the vehicle is absolutely criminal.
My first proper job in my career was IT for a maritime navigation company. This must have been around 2000, and we were selling these to normal people that have boats. I can't believe they did not integrate EPIRB into something like this triggered by an emergency trigger within the vehicle: https://en.wikipedia.org/wiki/Emergency_position-indicating_...
The facts that even if the unclear "7 ways" to surface in case of emergency, that a) the ship doesn't know where the submersible is located, which GPS would easily solve for and b) if it does manage to use one of these seven ways there's no way to exit the vehicle is absolutely criminal.
Just add a line. It's only 2 miles.
Apparently having a tether is not a bad option. So what’s the reason they didn’t go for it?
Possibly because they were closing in a wreck and a tether can get snagged
And I guess they were doing very close flyby, visibility down there is real bad.
And I guess they were doing very close flyby, visibility down there is real bad.
yep, they have to get pretty close to see much.
https://www.youtube.com/watch?v=UCwg2h7i4Ac
I could imagine the plan to go near or inside a sunken ship has to do with this?
I’ve been wondering this too, and surprised that none of the news reports have addressed it. Would love to hear from someone knowledgeable on whether it’s feasible and what the limitations and trade-offs are (eg, unreasonably high risk of entanglement).
How would you track your location underwater? What's your reference?
They don't have any GPS signal down there...
They don't have any GPS signal down there...
With sonar. The submarine doesn't have to locate itself, it just needs to be active pinging and it can be triangulated.
Radio doesn't work underwater, but sound actually travels incredibly far (hence why military subs go all out with noise reductions).
Edit: I mean the real question is why the hell does this thing not have some type of system like this already? You know the upfront expected dive time, so set a couple of noisemakers on the exterior hull to go off after you exceed it.
Radio doesn't work underwater, but sound actually travels incredibly far (hence why military subs go all out with noise reductions).
Edit: I mean the real question is why the hell does this thing not have some type of system like this already? You know the upfront expected dive time, so set a couple of noisemakers on the exterior hull to go off after you exceed it.
I am not a marine noise expert, but it’s my understanding that noise transmits horizontally underwater way better than vertically. Since this sub is going really deep, getting the pings to go ‘up’ to a meaningful degree is going to be difficult.
This is correct, the different temperatured layers of water typically develope quite well defined borders, these border regions act like any border between mediums with differing densities: they refract and reflect waves passing through them.
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If the banging hasn't been heard since could the sounds be related to the vessel imploding? Oxygen tanks or similar rupturing? You'd think if the passengers were still alive they'd continue to make noise at regular intervals or at least try to bang out an S-O-S in Morse code.
I don't know how they could be retrieved successfully since the US Navy DSRV crush depth is only 5,000 feet; the only hope they have if they're still alive, is to get the propulsion back so they can maneuver to a more shallow depth.
So sad.
While it's easy to be wise after the event, this thing does seem to be rather too Heath Robinson to be safe considering the extraordinarily challenging nature of the environment it operates in.
Maybe they can use mores code?
Mores code
I am not even sure why we are looking for them, I don't think there is any way to setup rescue equipment that can go low enough to help them and drag that submersible out of the water before they would run out of oxygen.
The French research ship Atalante is almost there:
"It carries the Victor 6000 autonomous robot, capable of descending to a depth of 6,000 metres, beyond the 3,800 metres of the wreck's position"
https://www.reuters.com/world/europe/france-send-ship-titani...
Last I checked on MarineTraffic Atalante was about 100NM away from site. Would it not help?
"It carries the Victor 6000 autonomous robot, capable of descending to a depth of 6,000 metres, beyond the 3,800 metres of the wreck's position"
https://www.reuters.com/world/europe/france-send-ship-titani...
Last I checked on MarineTraffic Atalante was about 100NM away from site. Would it not help?
That is good but probably one of the best/only tools for the job. It is probably already too late though.
All that is still theory, we don't even know if the submersible isn't already destroyed.
All that is still theory, we don't even know if the submersible isn't already destroyed.
Maybe they could attach a cable and drag it up to a ship? I'm sure there's ways to help these people with joined effort
And with which equipment would you do that? Are there even submersibles with adequate tooling available in a small enough radius?
I've followed an OceanGate Titanic mission where a popular travel blogger was participating in and from what I understood there aren't many submersible vessels in the world able to go so low, let alone with functionnal tools. It is not like you can open the door to a diver for him to attach a cable, pressure is just too high.
I've followed an OceanGate Titanic mission where a popular travel blogger was participating in and from what I understood there aren't many submersible vessels in the world able to go so low, let alone with functionnal tools. It is not like you can open the door to a diver for him to attach a cable, pressure is just too high.
This is barely on topic, but "there aren't many submersible vessels in the world able to go so low" caught my eye and I will use this opportunity to throw shade on the US DoD as partially responsible for the lack of such vehicles in current day. Yes, I'm pretty salty about this one.
The small submersibles used for Titanic the movie for filming the wreckage were Mirs* and a marvel of engineering for their time. However "[t]he level of technology flowing into the Soviet Union raised concern in the US and Rauma-Repola [the Finnish manufacturer] was privately threatened with economic sanctions."
* https://en.wikipedia.org/wiki/Mir_(submersible)
The small submersibles used for Titanic the movie for filming the wreckage were Mirs* and a marvel of engineering for their time. However "[t]he level of technology flowing into the Soviet Union raised concern in the US and Rauma-Repola [the Finnish manufacturer] was privately threatened with economic sanctions."
* https://en.wikipedia.org/wiki/Mir_(submersible)
I can't imagine what is potentially going through their heads. If they are alive the 8 hour delay from Oceangate on reporting the incident to the USCG is likely going to result in massive liability, possibly criminal. Deep Sea rescues are extremely improbable and minutes matter let alone hours.
I have a hard time believing that this report is accurate but, it's possible. My best friend works at the lab that tests and certifies deep sea vessels for the navy, manned and unmanned, and he's 99% sure they're already gone due to an implosion. He actually was involved in the testing of one of their prototypes so has a pretty intimate knowledge of their construction. Cyclical fatigue on the carbon fiber hull is the likely culprit if such was their fate.