Three people died and seven others were rescued Friday after a boat capsized in Geneva Lake as a strong storm passed through southern Wisconsin, an official said.

Many injuries were reported in Wisconsin’s Walworth County after the storm toppled trees, knocked down power lines and damaged buildings, said Tom Hausner, undersheriff for the Walworth County Sheriff’s department.

Hausner said he did not know any other information about the people who died and those rescued.

Police in the city of Lake Geneva are investigating, Hausner said. Officials there didn’t immediately respond to an email and voice message from The Associated Press seeking more information.

Lake Geneva Mayor Todd Krause declared an emergency and said that one person had minor injuries after being struck by a falling tree. Several areas of the city were experiencing power outages, he said in a statement.

Hausner said county authorities received multiple 911 calls reporting damage and people trapped in buildings and seeking help. He said deputies responded immediately but were delayed by downed power lines and trees blocking streets.

“Power lines are all over the place. We are urging people to stay away,” he said.

Hausner said his agency asked for help from law enforcement in nearby counties and the Wisconsin Department of Natural Resources.

Geneva Lake, in southern Wisconsin, attracts tourists from the Chicago area and other parts. The population in Walworth County, where the lake is located, nearly doubles during holiday weekends, Hausner said.

The storms that rolled through the Midwest on Friday afternoon and evening prompted multiple cities to cancel holiday festivals and reschedule fireworks displays.

The National Weather Service issued a severe thunderstorm watch for Lake Geneva, Wisconsin, saying the forecast showed heavy rain Friday with lingering showers into Independence Day and a continued chance of showers and thunderstorms throughout the weekend.