(AP) — Two big rigs and two passenger vehicles collided and spilled diesel fuel across a Florida highway Thursday, sparking a massive fire that killed six people, authorities said.

The wreck happened on Interstate 75 about a mile south of Alachua, near Gainesville. The flames were fed by about 50 gallons of diesel, authorities said.

Eight other people were taken to the hospital, some with critical injuries, the Gainesville Sun reported.

Emergency crews extinguished the fire and said they were treating the crash as a homicide investigation. The fire was so intense that authorities said it damaged parts of the road.