About 500,000 customers still won’t have electricity into next week as wide outages from Hurricane Beryl persist and frustration mounts over the pace of restoration, an official with Houston’s biggest power utility said Thursday.

Jason Ryan, executive vice president of CenterPoint Energy, said power has been restored to more than 1 million homes and businesses since Beryl made landfall on Monday. The company expects to get hundreds of thousands of more customers back online in the coming days, but others will wait much longer, he said.

“We know that we still have a lot of work to do,” Ryan said during a meeting of the Texas Public Utility Commission, the state’s utility regulation agency. “We will not stop the work until it is done.”

Ryan predicted that the prolonged outages into next week would be concentrated along the Texas coast, closer to where Beryl came ashore.

The Category 1 hurricane — the weakest type — knocked out power to around 2.7 million customers after it made landfall in Texas on Monday, according to PowerOutage.us.

CenterPoint Energy has struggled to restore power to affected customers, who have grown frustrated that such a relatively weak storm could cause such disruption at the height of summer.

Area residents have complained that the utility and state and city officials were not ready for the storm, that the restoration process has been slow and that CenterPoint’s online map that is supposed to show where power in back on has been woefully inaccurate, sometimes showing entire neighborhoods as restored when they were still without power.

The company acknowledged that most of the 12,000 workers it brought in to help the recovery were not in the Houston area when the storm arrived. Initial forecasts had the storm blowing ashore much farther south along the Gulf Coast, near the Texas-Mexico border, before it headed toward Houston.

Ryan said the vast majority of outages were caused by falling trees and tree limbs, and workers had to conduct damage surveys on more than 8,500 miles of power lines.

Beryl has has been blamed for at least eight U.S. deaths — one each in Louisiana and Vermont, and six in Texas. Earlier, 11 died in the Caribbean.

The storm’s lingering impact for many in Texas, however, was the wallop to the power supply that left much of the nation’s fourth-largest city sweltering days later in hot and humid conditions that the National Weather Service deemed potentially dangerous.

“Maybe they thought it wasn’t going to be so bad, but it’s had a tremendous effect. They needed to be better prepared,” construction worker Carlos Rodriguez, 39, said Wednesday as he gathered apples, oranges and ready-to-eat meal packs at a food distribution center. His family, with two daughters ages 3 and 7, was struggling, he said.

“We have no power, we’re going to bed late and I’m using a fan made out of a piece of cardboard to give my kids some relief,” Rodriguez said.

Hospitals were sending patients who could not be released to homes with no power to a sports and event complex where an area was set up to hold as many as 250 people. As of late Wednesday afternoon, about 40 patients had arrived and about 70 to 75 others were on their way, Office of Emergency Management spokesman Brent Taylor said.

Gov. Greg Abbott, who is in Asia on an economic development trip, questioned why Houston has repeatedly been plagued with power problems after severe weather. In an interview with Austin television station KTBC, Abbott, who has been governor since 2014, said he would direct the Texas Public Utility Commission to investigate that, as well as the preparations for and response to Beryl.

Meanwhile, Houston Mayor John Whitmire bluntly called on the utility to do a better job.

“That’s the consensus of Houstonians. That’s mine,” Whitmire said.