A medical helicopter crashed into the Potomac River (search), killing at least one person. One man was rescued from the river and a third person remained missing Tuesday.

The Life Evac (search) helicopter went down just south of the Woodrow Wilson Bridge (search) around 11 p.m. Monday.

Authorities said the helicopter just competed a dropoff at the Washington Hospital Center (search) in Washington and was returning to its base in Stafford, Va., when it went down. No patient was said to be on board.

"I saw a helicopter come across the bridge," said Maryland State Police Sgt. Billy Dunston, who was stationed at the Wilson span. "It looked pretty low to me when it went across, but I didn't see it come out the other side."

A passer-by, Arthur Stewart, helped Dunston by pinpointing where the helicopter went into the water.

"It didn't seem real. I thought it would go down and come back up," said Stewart, 39, of Washington.

Late Tuesday morning, a crane hauled out the wreckage of the helicopter out of the river. The nose and tail were both sheared off, and were pulled up in separate pieces, along with several other bits of debris.

The survivor, identified as Jonathan Godfrey, was in fair condition at Washington Hospital Center. He was plucked from the water by a fire department rescue boat.

"We got a little closer and that's where we found the victim, hanging on to the tail section," said firefighter Tom Wheatley with the Alexandria, Va., Fire Department. "He was halfway in and out of the water, and he was hanging on with the good arm that he had."

The aging Wilson bridge is being replaced with a new span, and there are many large cranes at the site. Authorities said they don't know if they played a role in the accident.

The survivor was interviewed and believes the helicopter may have hit something, police said.

A National Transportation Safety Board (search) investigation was launched.