Pressures in NG pipelines dropped because TX grid managers didn't know which circuits provided power to the wells or the vital compressor stations, and they blacked out those circuits, creating a death spiral they couldn't recover from. Sounds like they had no contingency planning in place for such a situation, assuming it would never happen - in my old line of biz, we needed to have backup plans for backup plans, failure trees went down to 3 or 4 levels.