ROSEVILLE, Calif. (AP) — Investigators say they are working around the clock as they struggle to determine why a man with no apparent ties to terrorism drove a flaming minivan full of propane tanks and gasoline cans through the main gate of a major Northern California Air Force Base this week.

FBI agent Sean Ragan said Friday that 51-year-old Hafiz Kazi died in the minivan after veering through the gate at Travis Air Force Base and crashing Wednesday night.

Kazi had no known links to terrorism, did not leave behind a manifesto or any threats or explanation, and a video found on a cellphone provided no clues.

It was only after the fire was out that rescuers realized the minivan was loaded with propane tanks and gasoline cans.