(PIGEON FORGE, Tenn.) -- A post-crash fire has "complicated" the investigation into a sightseeing helicopter crash that killed five people near the Smoky Mountains in eastern Tennessee, according to the National Transportation Safety Board.
NTSB senior air safety investigator Luke Schiada said this afternoon that what is left of the Bell 206 helicopter is "extremely fragmented" due to the a post-crash fire. They said it is too early to say what caused the helicopter to go down.
"The fact that the wreckage was consumed by the fire does make things more complicated," Schiada said at a news conference.
Schiada said evidence indicates the helicopter struck a ridge before crashing into the ground, killing all four passengers and the pilot.
The helicopter was on a 12-minute flight, the second of the day for the pilot, he said.
The tourist helicopter was built in 1977 and operated by Smoky Mountain Helicopters, Schiada said at the news conference.
Authorities have not released the names of the victims.
The NTSB said it is looking into aircraft maintenance records and pilot history, as well as environmental conditions.
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