MILWAUKEE — Searchers on Tuesday found the body of a 10-year-old boy who was swept away in a Milwaukee drainage ditch following severe thunderstorms that brought heavy rain and damaging winds to a wide swath of the Midwest and parts of the South.

The boy’s body was found during a search of the city’s drainage tunnels, WITI-TV reported. Two adults in their 30s who entered the water in an attempt to rescue the child Monday evening were still missing, according to Milwaukee fire and police officials.

Firefighters focused their search Tuesday on three connected tunnels that carry water to the Kinnickinnic River. Search crews did not enter the tunnels Monday night because of dangerous conditions and instead sent a drone inside in an attempt to locate the three, officials said. Police said all three knew each other, but didn’t elaborate.

The water was deep and fast-flowing following the severe storms, which also caused damage in Illinois, Indiana, Michigan and Ohio. And the storms also packed a punch early Tuesday as they rolled into West Virginia, where numerous roads were closed by downed trees and power lines.

According to the website PowerOutage.us, which tracks outages nationwide, more than 400,000 electric customers in Illinois, Indiana, Michigan, Ohio and West Virginia were without service Tuesday afternoon.

The storms came as high temperatures and humidity settled in over states stretching from parts of the Gulf Coast to the Great Lakes and eastward to the Carolinas. More than 100 million people were facing combination of heat advisories, excessive heat warnings and excessive heat watches through Wednesday following record weekend temperatures in parts of the West and the Southwest.

In Illinois, a supercell thunderstorm with winds in excess of 80 mph toppled trees and damaged power lines Monday evening as it left a trail of damage across the Chicago area and into northwestern Indiana, the National Weather Service said.

Numerous reports of wind damage were reported along the storm’s path, with Chicago’s O’Hare International Airport recording an 84 mph wind gust, the weather service said. Tornado sirens sounded in Chicago as the storm rumbled in, and crews were assessing the damage Tuesday to determine if any twisters touched down.

In Bellwood in Chicago’s west suburbs, village officials said winds stripped the roof off an apartment building, injuring a young woman who was hospitalized after being hit by falling debris but was expected to be fine.

“We just heard people screaming that the roof was off, get out, get out,” resident Larhonda Neal told WLS-TV.

In northwestern Indiana, the weather service reported storm damage in Ogden Dunes and said hail 1.5 inches in diameter pummeled the Lake County town of New Chicago on Monday night.

In northeastern Indiana, the weather service said a 98 mph wind gust was recorded at Fort Wayne International Airport, the strongest wind the airport has ever recorded, eclipsing the previous record of a 91 mph gust recorded on June 30, 2012. Extensive storm damage and downed trees were reported in Fort Wayne, where winds ripped siding and insulation from the hangar of SkyWest, an aircraft maintenance company southwest of the Fort Wayne airport’s terminal and runways, exposing the planes inside, WANE-TV reported.

Thunderstorm clusters in the lower Great Lakes region met the criteria to be considered a derecho, the National Weather Service tweeted Tuesday. A derecho is a widespread, straight-line wind storm that is associated with fast-moving severe thunderstorms.

In northern West Virginia, three firefighters were taken to a hospital for evaluation after responding to an electrical fire early Tuesday in Wheeling, the city about 30 miles southwest of Pittsburgh said in a news release. Two firefighters were shocked by a power line that fell on the roof of a building which had caught fire during the storm. The third firefighter was injured in a fall.