evidence: As Texas faced record-low temperatures in February 2021 and snow and ice made roads impassable, the state’s electric grid operator lost control of the power supply, leaving millions without access to electricity. As the blackouts extended from hours to days, top state lawmakers called for investigations into the Electric Reliability Council of Texas, and Texans demanded accountability for the disaster. The Texas Tribune covered the impact of the storm in real time and continues to bring accountability coverage as officials address the issues exposed by the storm. [...] Millions of Texans have gone days without power or heat in subfreezing temperatures brought on by snow and ice storms. Limited regulations on companies that generate power and a history of isolating Texas from federal oversight help explain the crisis, energy and policy experts told The Texas Tribune. [...] Energy and policy experts said Texas’ decision not to require equipment upgrades to better withstand extreme winter temperatures, and choice to operate mostly isolated from other grids in the U.S. left power system unprepared for the winter crisis.