MISSOULA, Mont. (AP) — Three airplane fuselages that slid down a steep embankment into the Clark Fork River following a train derailment in western Montana could take until Tuesday to remove, railroad officials said Sunday.

"The progress is going extremely slow," Montana Rail Link spokeswoman Lynda Frost said. "If we get one up today, it would appear it will take one day each to get them out."

She said a crew of 50 with eight heavy-equipment machines was working together to hoist up the three Boeing 737 fuselages, the large, central portions of planes that hold passengers.

Six fuselages were aboard a westbound train when 19 cars derailed Thursday about 10 miles west of Alberton. The three remaining plane sections also fell off but stayed on land. No one was injured in the derailment, which is under investigation.

Boeing said in a statement that it has experts at the scene to assess the damage. Marc Birtel, director of media relations, said Sunday that he didn't have information on what the experts have decided.

The fuselages were traveling from a Spirit AeroSystems plant in Wichita, Kansas, to a Boeing facility in Renton, Washington, to be assembled into airliners.

Ken Evans, senior manager for Spirit AeroSystems, said the company ships 42 of the 737 fuselages each month to Washington state.

"We're at a record rate right now," he said. "We've been doing this for decades, and this is exactly how they've been shipped for decades."

None of the companies involved offered an estimate of the damage.

Frost of Montana Rail Link said insurance considerations won't be decided until the investigation is complete. She said the train was traveling well under the 35 mph speed limit for that section of track.

Meanwhile, rafters on the popular Clark Fork River have a surreal view as they pass the fuselages near a river feature called Mermaid Rock.

"They really get to see the enormous size of those aircraft," said Josh Flanagan of Wiley E. Waters, a rafting company. "It's not something you expect to float past when you're on a river trip."