Two spans of a southwest Kentucky bridge collapsed after being struck by a cargo ship that carried aviation parts. No injuries were immediately reported, state transportation officials said.

The Delta Mariner struck the main span of the Eggner Ferry Bridge on Thursday evening at U.S. Highway 68 and Kentucky Highway 80, said Keith Todd, spokesman for the Kentucky Transportation Cabinet. State inspectors are on their way to determine how much of the bridge, which opened to traffic in 1932, was damaged.

"At this point, we don't believe there was any loss of life," Todd said.

He said there also were no injuries on board the boat. He was unable to say where the ship was traveling when it struck the bridge.

Officials said the bridge was closed to traffic, causing vehicles needing to cross the Kentucky Lake reservoir and the Tennessee River to be detoured for dozens of miles. The Coast Guard also blocked access to boat traffic at the bridge site.

Robert Parker, 51, of Cadiz, Ky., said he and his wife were traveling northbound on the highway after leaving his stepson's house in Murray, Ky. They were driving in the rain along the darkened bridge around 8 p.m. when they suddenly noticed a missing 20-foot piece of the bridge, which at that section stands at least 20 feet above the water.

"All of a sudden I see the road's gone and I hit the brakes," he said. "It got close."

Parker said he stopped his pickup within five feet of the missing section. Two cars behind him stopped on his bumper and he saw another car on the other side of the missing section stopped.

He said he didn't feel the vessel strike the bridge but "felt the bridge was kind of weak." They had to detour about 50 miles to return home to Cadiz.

Officials say about 2,800 vehicles travel daily on the bridge, which already was in the process of being replaced, although the new bridge has not been built yet. Motorists have been advised to take alternate routes.