“Both the PUC Chair and the ERCOT CEO said they were prepared the day before the storm hit in full force, but obviously they were not,” Patrick said in a statement. His statements come after the officials testified for hours late last week in committee hearings as state lawmakers grilled them over the power grid failures.

ERCOT and PUC officials did not immediately respond to requests for comment.

The week of Feb. 14, freezing temperatures and snow caused mass power outages and water issues and left dozens of people dead. ERCOT, the state’s electric grid operator, lost control of the power supply and began implementing rolling blackouts which turned into power outages for as many as 4.5 million customers at one point across the state that lasted days.

Patrick said PUC and ERCOT officials were not ready for a winter storm of this magnitude and were given ideas for ways to prepare, but failed to do so.

“Our state senators repeatedly asked for their analysis and suggestions regarding what could have been done differently and what needs to be done going forward to prevent a similar problem in the future,” Patrick said.

Both Walker and Magness testified in hearings that they were adequately prepared before the storm, but admitted to him after the power failure that their testimony was inaccurate, Patrick said.

“I do not make this call for the resignation of the PUC Chair and the ERCOT CEO lightly,” Patrick said. “The lack of adequate preparation by both the ERCOT CEO and the PUC chair prior to the storm, their failure to plan for the worst-case scenario and their failure to communicate in a timely manner dictates they are not the ones to oversee the reforms needed.”

Other members of the legislature have also called for accountability in response to the power crisis. On Friday, state Rep. Rafael Anchia, D-Dallas, called for Walker to resign, saying “her inability to even muster an apology to Texans who endured freezing temperatures without heat or power and resulted in loss of life is inexcusable.”

Seven ERCOT board members have already resigned after the power grid almost collapsed and lawmakers criticized the companies. All but one of the board members who resigned live outside of Texas.