Update: Fire 80% Contained After 2 Marine Helicopter Pilots Killed in Crash at Camp Pendleton

Updated at 2:30 a.m. Tuesday.

An investigation into Monday's helicopter crash on Camp Pendleton that killed two Marines continues Tuesday, with the fire sparked by the accident largely contained.

The crash ignited a brush fire that burned 120 acres, base officials said. It was 80 percent contained by Monday evening.

The AH-1W Cobra went down about 1 p.m. Monday during a routine training exercise in the southeast corner of the base, near Fallbrook.

The pilot and co-pilot aboard the 3rd Marine Aircraft Wing helicopter were pronounced dead at the scene by emergency responders, officials said. Their names have not yet been released.

The fire spread quickly, burning 50 acres within three hours after the crash.

Camp Pendleton firefighters, along with other units from Cal Fire, the U.S. Forest Service and the Fallbrook Fire Department, used at least four air tankers, four helicopters tankers, five strike teams, 12 hand crews and one forward air control aircraft to contain the fire, which burned in the southeast portion of the base near the border with De Luz and moved northeast, officials said.

The fire was about 80 percent contained and did not pose the threat of base evacuation by Monday night.

The crash is under investigation. No details about what may have caused the crash have been released.