LOMPOC, Calif. -

Authorities say a Ventura County firefighter has died after the truck he was in rolled over multiple times Wednesday morning.

Ventura County Fire Chief Mike Lindbery announced the tragic loss of Fire Engineer Ryan Osler in line of duty vehicle.

The accident happened at about 6:20 a.m. on state Route 246 at Purisima Road in Lompoc.

"We are trying to determine how the fire truck actually ran into the roundabout at Purisima," says Srgt. Dan Clotworthy, with the California Highway Patrol.

Officials on the scene of the accident say two firefighters were in the Ventura County water tender truck when it crashed. They were headed to help fight the Canyon Fire at Vandeberg.

"It's from what we understand it's loaded with about 2000 gallons of water and they use that for fire suppression and putting out spot fires," says Srgt. Clotworthy.

The passenger was pronounced dead on scene. The driver self-extricated from the wreck and was taken to Lompoc Valley Medical Center with minor to moderate injuries, according to Capt. Dave Zaniboni.

The California Highway Patrol says the deceased firefighter was trapped inside when the vehicle crashed.

Officials are calling the accident tragic.

"We are extremely saddened at the loss of a firefighter, one of our brothers in uniform in route to help others and it's the sadness of what we do as emergency responders," says Srgt. Clothwothy.

The CHP is investigating the cause of the crash.