"When Texas lawmakers met last month to begin sifting through the wreckage of the state’s energy grid, many expected to hear tales of poorly insulated power plants rendered inoperable by the latest winter storm.
Instead, energy executives raised an even more confounding problem: dozens of natural gas facilities had not filled out a three-page application for outage exemptions before the storm, meaning their facilities lost power at a moment when their fuel was needed most to feed struggling power plants."
This on its own doesn't excuse the multitude of other ways that power generators in Texas failed to prepare (lack of weatherizing, lack of backup power supplies, etc.) but this is just another part of the big picture.