Thunderstorms that produced hundreds of lightning strikes and hail as large as baseballs pounded western Maine and York County on Sunday night.

During the storms, at least one structure fire and car accident were reported in the areas hardest hit by the storms, but police dispatchers were unable to say with certainty that they were weather-related.

The storms knocked out power to more than 5,500 homes and businesses, with more than 4,800 outages reported in York County late Sunday night by Central Maine Power Co. Hollis, a town in York County, was hit the hardest by the storms, with more than 1,200 customers losing power.

WCSH-TV meteorologist A.J. Burnett reported that a motorist in Denmark was struck by lightning while seated inside the vehicle. A Denmark firefighter, who responded to the incident, was also hit by lightning. Attempts to reach the Denmark Fire Department were unsuccessful.

“Haven’t seen lightning frequency like this in a very long time,” Burnett tweeted Sunday. “Amazing lightning with storm around Sanford. Nearly 400 strikes registered in 15 minutes.”

A structure fire in Alfred at 107 Kennebunk Road may have been caused by a lightning strike, and the Maine State Police said an accident on 32 Fall Road in Lebanon may have been weather-related. Additional details were not available about those incidents.

Margaret Curtis, a meteorologist with the National Weather Service in Gray, said the storms generated torrential rains and huge chunks of hail in some places.

The largest hailstone was recorded in Lebanon, on the New Hampshire border. Curtis said it measured 2.75 inches in diameter, or about the size of a baseball.

“York County saw the most hail, but the town of Naples was also hit hard,” she said. In Naples, hail 1.5 inches in diameter fell.

Rainfall was heavy during the evening, with central New Hampshire receiving more than 3 inches. The rainfall amounts in Maine were not as substantial, Curtis said, because the storms moved quickly through the region.

Curtis said one of the most interesting features of Sunday’s thunderstorms was the amount of lightning strikes. She said more than 1,500 lightning strikes were recorded in southern Maine between 8 and 9 p.m.

It will be hot on Monday with temperatures reaching into the high 80s, but it should be dry, Curtis said.