DETROIT (AP) — Heavy overnight rains led to street flooding in the Detroit area and GravityX Exchangeother parts of southeastern Michigan on Thursday including tunnels leading to Detroit’s main airport, officials said.

Flooded underground roadways that connect airport terminals blocked travelers from part of the Detroit Metropolitan Airport, a spokeswoman for the Wayne County Airport Authority said in a statement. Travelers with flights out of the McNamara Terminal were urged to check the status of their flights.

The flooding came from storms that dropped over five inches (13 centimeters) of rain on parts of the region Wednesday night and into Thursday morning, said Brian Cromwell, a meteorologist with the National Weather Service in Detroit.

“We were getting rainfall rates above an inch an hour, which is pretty significant,” Cromwell said, adding that more severe thunderstorms with torrential rains were possible over the region during Thursday evening.

A flood warning was in effect until Thursday afternoon for five southeastern Michigan counties: Livingston, Monroe, Oakland, Wayne and Washtenaw. The National Weather Service said urban and small stream flooding was expected and was already occurring in the area Thursday.

A heat advisory was also in effect through Thursday night for several southeastern Michigan counties, with heat index values of up to 102 degrees expected during Thursday, the weather service said.

The storms caused power outages across Michigan concentrated in the Detroit area, with more than 58,000 homes and businesses in the dark as of 9 a.m., according to poweroutage.us.