The Oklahoma Highway Patrol identified the victims of a fatal crash on Interstate 40 near Okemah on Friday.
According to the OHP, the wreck happened when a dump truck that was westbound in the outside lane slowed down to turn across the center median. It was hit by a passenger van that was also westbound in the inside lane, troopers said.
The van caught fire after the crash and other drivers pulled the victims out, according to troopers.
The OHP report says the driver of the dump truck was Daniel Forbus, 61, of Conroe, Texas. He was not hurt, troopers said.
The driver of the 2013 Chevy Express van was Sean Connell, 34, of Amarillo. The OHP said he was in critical condition in a Tulsa hospital.
One passenger -- Kristopher Youngberg, 41, of Amarillo -- died at the hospital in Okemah.
The OHP said the other three passengers were in critical condition. They're identified as:
Kevin Coffman, 42, Amarillo
Christopher Waldrop, 39, Miami, TX
William Overshiner, 39, Miami, TX
The OHP said all five men in the van were employees of the Department of Energy in Amarillo.
Troopers said they're still investigating the wreck and don't have a cause yet.