FLAGSTAFF, Ariz. - An Arizona medical examiner will conduct autopsies on three British tourists who died after their sightseeing helicopter crashed in the Grand Canyon.

The Mohave County Medical Examiner's Office says autopsies on the trio are expected to be completed by Tuesday afternoon.

The victims have been identified as 27-year-old Becky Dobson, 27; her boyfriend, 30-year-old Stuart Hill; and his brother, 32-year-old Jason Hill.

Family members say they were celebrating Stuart Hill's birthday with a group of friends.

Four other people, including the pilot, remain hospitalized.

The EC-130 crashed Saturday on tribal land that has fewer regulations for air tours than the national park.