A search is underway for the body of a skydiving instructor who somehow became detached from his partner during a tandem jump from an airplane Thursday afternoon.

The instructor and his tandem jump partner were about one mile above the ground when they became separated, said Steve McCausland, spokesman for the Maine Department of Public Safety. The instructor did not have a backup parachute.

“The fall was not survivable,” McCausland said.

The incident led to a search of the area near Skydive New England in Lebanon, where the flight originated. Maine Game Wardens, forestry personnel and police in an aircraft conducted the search, but were unable to find the instructor’s body.

McCausland said game wardens will resume the search Friday morning. The name of the missing instructor is not being released.

The incident took place around 2 p.m. and was reported by the second skydiver involved in the tandem jump, who landed safely with a parachute.

Police do not know how the two became separated.

In a tandem jump both people jump together with the same parachute. According to Skydive New England’s website, tandem jumps take place at an altitude of 14,000 feet.