(KTEN) -- In the wake of last month's massive winter storm power failures, Texas Lieutenant Gov. Dan Patrick on Monday called for resignations from the chair of the state's Public Utility Commission and the president of the Electric Reliability Council of Texas.

Forced blackouts during the storm left more than 4 million homes and businesses in the dark, and the state's entire electrical grid was said to have been within minutes of total collapse.

Patrick said PUC chief DeAnn Walker or ERCOT's Bill Magness were unable to adequately address the challenges of the storm during hours of testimony to state lawmakers last week.

"Both the PUC Chair and ERCOT CEO said they were prepared the day before the storm hit in full force, but obviously they were not," Patrick said in a written statement.  He continued:

"From their testimony it is clear they also did not consider the harsh freeze could shut down electricity generating power plants or that crews would not be able to make emergency repairs because roads would be impassable. Their projections did not accurately calculate the impact of diminished wind power that would be lost in the storm combined with the loss of 14,000 megawatts of power they knew would not be available due to power plants that had been shut down for maintenance. These two issues alone accounted for hundreds of thousands of homes being without power and threatened a statewide blackout."

The lieutenant governor pledged that state lawmakers will mandate reform of ERCOT and ensure the stability of the electrical grid.

"I remain committed to making sure this problem is fixed so that we are prepared to face a power challenge like this should a major storm happen again," Patrick said.