At least seven people were killed and several others injured in a fiery crash on Interstate 75 in Alachua County Florida, near Gainesville.
At least 50 gallons of diesel fuel spilled in the accident, helping to feed the fire.
Two tractor trailers, a van and a midsize sedan were involved in the crash about 3:40 p.m. ET on I-75 southbound, the Florida Highway Patrol said.
"There was significant damage with the two tractor trailers and with that much abrasion, I'm not surprised that we had a fire," Lt. Patrick Riordan, of the Florida Highway Patrol, told NBC News. "There's large portions of the vehicle with metal. You've got aluminum, steel and a lot of other metals that are touching."
Authorities initially said six people died and eight people were taken to the hospital, many with critical injuries. The death toll climbed Thursday night to seven.
A helicopter landed on scene to search for injured people who may have been in nearby woods, Alachua County Fire Rescue officials said.
All lanes of the interstate, northbound and southbound, were shut down as of 5 p.m. ET
Riordan said he expected the highway to remain closed for much of the night.
"I think we've got a long night ahead of us. We've got a lot of debris, we've got a lot of damage to the road," he said. "We've got a lot of work ahead of us with regard to the investigation."