TRAVIS AIR FORCE BASE (CBS SF & AP) — A driver breached the main security gate at Travis Air Force base Wednesday evening and then crashed and died when his vehicle exploded into a massive fireball. Investigators are treating the incident as an act of terrorism.

Law enforcement sources said the vehicle carried propane tanks which the driver deliberately ignited after crashing through the security gate. The car drove off the road into a ditch and the driver died in the fire.

The driver has been identified by law enforcement, but has not been named, according to CBS News reporter John Blackstone.

No shots were fired. The FBI is joining the Air Force in the investigation of the security breach.

In short snapchat video clips posted of the incident on the Air Force Forum Facebook, the SUV bust into flames as military police raced toward the vehicle.

Travis Air Force Base officials say in a statement that the driver “gained unauthorized access” to the main gate around 7 p.m. Wednesday.

No one else was hurt at the air base, home to some 7,000 Air Force personnel.

“The safety and welfare of our Airmen, their families and our local community is our top priority,” said Col. John Klein, 60th Air Mobility Wing commander. “I am extremely proud of how our first responders quickly addressed the situation to keep Travis and the surrounding area out of harm’s way. We are fortunate to have enduring relationships with federal and local law enforcement, and will continue to work hand-in-hand with them through the investigation process.”

The Air Force Times reported Thursday that explosive ordnance disposal and Office of Special Investigations airmen were among the first responders on the scene.

The main gate to Travis was reopened some 12 hours after the incident. Officials said there was no known further threat to the base of the community.