The heaviest rain since 1925 engulfed the area on Monday, the second-wettest day on record, according to the National Weather Service.
Up to 6 inches of rain fell on Monday in a four-hour period and parts of five interstate highways that run through Detroit and many interior roads remained impassable on Tuesday, said Nicole Lisabeth, a Michigan State Police spokeswoman.
A 30-year-old woman died Monday after suffering a seizure in her car on a flooded road in Warren, a suburb north of Detroit, Lisabeth said. The storm may have also claimed a 100-year-old woman, whose body was found in her basement, she said.
Detroit's sewer systems were overwhelmed by the rain, Mayor Mike Duggan said in a statement.
Area residents on Tuesday dealt with flooded basements and power outages, and flood warnings from the National Weather Service remained in effect on Tuesday night.
Divers had checked about 70 vehicles left behind by motorists on flooded roadways and have found no one trapped, Lisabeth said. About 1,000 vehicles were abandoned on Monday in Warren, the city's mayor, Jim Fouts, told the MLive.com website.
The flooding forced General Motors Co to close a technical center in Warren and slowed operations of U.S. automakers in the region.