Autopsies from a fiery helicopter crash at the Grand Canyon earlier this year show two British tourists aboard died of smoke inhalation and burns that covered 100 percent of their bodies.
The Mohave County Medical Examiner's Office released autopsy reports Wednesday for 27-year-old Rebecca Dobson and 31-year-old Jason Hill. They died at the scene, along with Hill's brother, 30-year-old Stuart Hill.
Jonathan Udall and his wife, Ellie, died at a hospital.
The reports say Dobson and Hill were burned beyond recognition. There also was evidence they suffered carbon monoxide poisoning.
Udall's family is suing the helicopter owner and manufacturer. The wrongful-death lawsuit says he would have survived if the aircraft had a crash-resistant fuel system.
The Feb. 10 crash also critically injured two others.