The questions have carried into the night at the state capitol as lawmakers continue to press for answers from the people who run and oversee the state's power system. All trying to figure out what caused the deadly and destructive outages that swept across the state last week.
On day one of the hearings much of the fire has been aimed at ERCOT, the non-profit that's supposed to ensure the state has enough electricity to keep the lights on.
And a growing list of people took aim at ERCOT’s CEO, Bill Magness, saying he did too little too late to warn that the state was headed for disaster.
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“This is the largest train wreck in the history of deregulated electricity,” said state Sen. Brandon Creighton, R-Conroe.
The frustration poured out as senators grilled Magness for hours.
Among the questions, why he did not do more to alert state leaders that the incoming winter storm was so big, it threatened to cripple the state's electric system.
Magness said his team warned power plants several times the approaching weather could do damage.
But some senators argued the storm's devastating results prove ERCOT did not ensure that power plants were prepared.
Senators hammered Magness, saying that it was obvious the steps ERCOT took to prepare for the storm and manage the power flow didn't work. Magness replied that his team worked to prevent an uncontrolled blackout that would likely take weeks to recover from, but that he realized people were still left in the cold and in the dark for days on end.
Meanwhile, power company executives testified in the house suggested ERCOT actually caused some outages by allowing the grid to come so close to a total collapse
As the storm hit, ERCOT records show the electric grid was so stressed it dropped below the frequency it’s supposed to operate on for more than four minutes.
Energy companies said that caused some generators to trip off line.
“If frequency goes very fast down, or very fast up, it creates tremendous issues for the plant operators,” said Mauricio Gutierrez regional President of NRG.
When questioned about that in the senate, Magness said he had not seen information to prove that happened but could not disprove it either.
“I don't know what evidence they're bringing to the table to say that if they're right, then absolutely will we have to do something, because there was something going on that we weren't seeing”, Magness said.
On Thursday night, Oncor CEO, Allen Nye testified that his team saw frequency issues so severe it brought the North Texas grid near the edge of what it can handle.
“At 2:02 a.m. Monday morning, we were within two one-thousandths of a percentage point of getting into the under frequency safety net”, said Nye.
Magness tried to reassure senators his team saved the state from a more devastating blackout that could have lasted months.
“I feel a great deal of responsibility and remorse about the event and will continue to investigate,” said Magness.
But some senators who watched his testimony were not convinced.
“This failure occurred on his watch. It's time for him to go,” said Dallas Senator Royce West.
Late Thursday, Senator West told NBC 5 ERCOT must be reformed.
“We had a complete failure of our energy grid in Texas how embarrassing - should have never happened,” said West.
The head of the Public Utility Commission was also questioned about why her agency did not do more to oversee ERCOT and make sure power plants were ready for the winter. She said the legislature gave her only very limited authority over ERCOT and the legislature has not passed any laws requiring power plants to take any specific steps to protect against the cold. Lawmakers have said they will consider those changes now.
The PUC had an open meeting scheduled for Friday morning but late Thursday night it was canceled so they can focus on the legislative hearing process.
NBC 5 Investigates wants to hear how the storm affected you. You can email us at Investigate@nbcdfw.com.