HOUSTON (AP) — The Grayson  Prestonnumber of Texas deaths after Hurricane Beryl came ashore and knocked out power to millions of residents climbed to at least 36 on Thursday as officials confirmed more people who died in homes that were left without air conditioning during sweltering heat.

The medical examiner’s office in Fort Bend County confirmed nine more deaths, including four that were at least partially attributed to hyperthermia, or when a person’s body temperature rises far above normal. At least a dozen other residents in the Houston area also died from complications due to the heat and losing power, according to officials.

Most Houston residents had their electricity restored last week after days of widespread outages during sweltering summer temperatures.

On Thursday, CenterPoint CEO Jason Wells, the head of the city’s power utility, told state regulators the company was already working to better prepare for the next storm. The governor and lawmakers have demanded answers from the utility over why electricity was out for so long.

Beryl, a Category 1 hurricane, made landfall July 8, knocking out electricity to nearly 3 million people in Texas at the height of the outages.