A massive water main break shut down the eastbound lanes of a suburban Detroit freeway Thursday, swamping some cars.

Stranded motorists scrambled onto the tops of their vehicles to escape the water, which was up to 4 feet deep in places.

George Ellenwood, spokesman for the Detroit Water and Sewerage Department, which operates the system, said the rupture occurred shortly after noon in a 48-inch main on the Interstate 96 service drive. It was unclear what caused the break, he said.

"I see five vehicles that are in the water almost near the top of the door," Ellenwood told WDIV-TV. "They appear to all have been evacuated, but the vehicles are trapped on the freeway."

Images of the break captured by television news helicopters showed what looked like a waterfall gushing down the freeway embankment and water bubbling up in a flooded area of the service drive above. Portions of the eastbound lanes were completely flooded.

Livonia Public Utility Manager Kevin Roney told WXYZ-TV the same main ruptured about three or four years ago.

"It's a major transmission drain," he said.

The water also was leaking into the westbound lanes of Interstate 96, slowing traffic in the area.

Officials said they were working to shut down water to the main and said they hoped to have the freeway open later Thursday.