Orland: A FedEx tractor-trailer crossed a grassy freeway median and slammed into a bus carrying high school students on a visit to a college, killing 10 people, authorities said.

Massive flames could be seen devouring both vehicles just after the crash, and clouds of smoke billowed into the sky until firefighters had quenched the fire, leaving behind scorched black hulks of metal. Bodies were draped in yellow plastic inside the burnt-out bus.

California Highway Patrol dispatchers said the drivers of the tractor-trailer and bus were among the dead. In addition to both drivers, the patrol says three adult chaperones and five teenage students were killed in the crash on Thursday. Their identities haven’t been released.

The crash happened a little after 5:30pm on Thursday on Interstate 5 near Orland, a small city about 100 miles (160 kilometres) north of Sacramento.

The bus was one of two that the admissions office at Humboldt State University had chartered to bring prospective students from California to tour the Arcata campus, Humboldt’s Vice President of Administrative Affairs Joyce Lopes said.

University police were trying to determine which school districts the students were from and fielding telephone calls from anxious parents, Lopes said.

“Our hearts go out to those who have been affected, and we are here to support them, and their families, in any way possible,” Humboldt State’s President Rollin Richmond said in a statement on the school’s website.

Humboldt State spokesman Simon Chabel said the school was working to confirm where in California the students on the wrecked bus are from.

Los Angeles Unified School District Superintendent John Deasy told the Los Angeles Times that several students from his district were on the bus but that he did not have an exact count.

A CHP dispatcher says the bus and truck were on opposite sides of the freeway when the truck crossed the median and slammed into the bus, causing an explosion and fire.

Investigators say the truck driver might have been trying to avoid a passenger car that was also involved in the crash, which shut down north- and southbound traffic on the freeway.

A first responder who helped set up a triage at the scene said 36 or 37 people received injuries ranging from severe to minor burns, broken legs and noses and head lacerations.

“The victims were teenage kids. A lot of them were freaked out. They were shocked. They still couldn’t grasp what happened,” Jason Wyman with the Orland Volunteer Fire Department said.

Bonnie Kourvelas, a FedEx spokeswoman, said in a statement on Thursday night: “Our thoughts and prayers are with everyone involved in the tragic accident on I-5 in California. We are cooperating fully with authorities as they investigate. ”