Eight people are dead following a collision between a Greyhound bus and truck near Thoreau, New Mexico.
Police say a tractor trailer traveling east on Interstate 40 blew a tire, shot across the median and hit the westbound Greyhound bus head-on.
Bus passenger Rachel Cunningham says she was asleep and woke up to a horrific scene.
"The side of the bus where we hit on was opened up like a can of sardines," she recalled.
She tried to help, but some people were already dead.
Dozens others are injured; one is in critical condition.
"Several patients will be going to the operating room today or tomorrow and probably several of them will have long road of recovery," said Dr. Sonlee West, a trauma surgeon at the University of New Mexico Hospital.
The crash was so powerful it threw debris hundreds of feet away.
Investigators want to know whether it was just the blown tire that sent the truck careening out of control, or if other factors contributed to the crash.
"Our vehicle factors group will look at overall maintenance, not only of the vehicles involved, of the motor coach and the tractor semi trailer, but also an examination of the fleet to fleet policies and safety culture of both of those organizations," said National Transportation Safety Board investigator in charge Pete Kotowowski.