(CNN) -- A charter bus in northern Oregon skidded on ice, crashed through a guardrail and tumbled several hundred feet down a steep embankment on Sunday morning, spilling passengers along the way.
"I've been a firefighter for 20 years and this is the first time I've ever seen anything like this," Pendleton, Oregon, fire Lt. Steven Brost told CNN affiliate KPTV. "It appeared that most of the patients had actually been ejected from the bus as the bus went down the cliff."
Nine people died in the crash, according to Oregon State police. At least 26 people were transported to St. Anthony Hospital in Pendleton for treatment. Five of them were later transferred to another hospital.
The driver suffered severe injuries and has not yet spoken to authorities, police said. The cause of the crash is under investigation.
The crash took place on Interstate 84 east of Pendleton, state police said. Emergency responders, including people trained for rope rescues, helped move victims up the embankment back to the highway.
About 40 people are thought to have been aboard the charter bus, which was returning to Vancouver, British Columbia, from Las Vegas, police said. The bus was operated by Mi Joo Tour & Travel out of Vancouver.
The westbound lanes of I-84 were closed near the crash site during the rescue and recovery effort.
CNN's Lateef Mungin contributed to this story.