Texas officials with the Energy Reliability Council of Texas (ERCOT) said the state's primary power grid was "seconds or minutes" away from catastrophic failure Sunday night, according to a tweet from NBC News' Gabe Gutierrez.
ERCOT officials said on Thursday that "significant progress" has been made in restoring power throughout Texas.
"We're to the point in the load restoration where we are allowing transmission owners to bring back any load they can related to this load shed event," ERCOT Senior Director of System Operations Dan Woodfin said. "We will keep working around the clock until every single customer has their power back on."
Just under 500,000 Texas customers remain without electricity, which is down from the more than four million who were in the dark earlier this week.
"At approximately 1:25 a.m. this morning [Feb 15] , ERCOT entered its third and highest level of emergency operations because electric demand is exceeding the available supply," said officials at that time. "Controlled outages are occurring to protect the electric grid from uncontrolled, cascading outages."
ERCOT officials said it would take weeks or even months to restore power throughout the state if the grid had collapsed entirely.