Marine City police said they received a call around 11:15 p.m. Sunday (July 4) about a car speeding on Broadway Street.
Officers went to the area and learned that a car was floating in the St. Clair River, police said.
Investigators determined the car had been traveling east on Broadway Street when it crashed through the steel guardrails at the river and went into the water.
Witnesses on a boat went over to the car but couldn’t get the occupants out as it sunk into the water, according to authorities.
Members of the St. Clair County Dive Team and firefighters from Algonac and Marine City searched the area for about 50 minutes before finding the car, officials said.
The bodies of two people -- an 83-year-old man and an 86-year-old woman -- were recovered, police said.