Charges are pending against the driver of a tour bus after it slammed into a tow truck assisting a car along the side of a B.C. highway Saturday morning.

BC ambulance says 38 people were injured in the crash — two of them with life-threatening injuries.

RCMP Sgt. Mike Pears said the tow truck had been called to assist a car after it hit a deer on the Coquihalla Highway about 30 kilometres south of Merritt.

He said both vehicles were pulled over to the side of the road.

"We've got one lane partially blocked," Pears said. "Traffic was slowing down and moving over. It was witnessed the bus was not slowing down, it did not appear to move over. All of a sudden it collided with the tow truck."

The tow truck had been responding to a car that hit a deer. (CBC)

Pictures from the scene show the front of the bus sheared off and a tow truck and red hatchback with extensive damage.

Pears said an employee of the tour bus company was seriously injured when he was ejected through the window and into the creek just below the highway.

Another bus passenger was also seriously hurt, said Pears, along with the tow truck driver and a person associated with the red car. He said the accident was entirely preventable and charges would be laid.

RCMP say this car hit a deer and was being assisted by a tow truck when both cars were hit by a tour bus that failed to slow down. (CBC)

At least 20 patients were taken to local hospitals in Merritt, Kamloops and Kelowna.

A spokesman for the Fraser Health Authority said that the Royal Columbian Hospital in New Westminster had cleared its trauma bay and was also prepared to accept patients from the crash.

Multiple ambulances rushed to crash scene

Twelve ground ambulances and four air ambulances were dispatched to the scene.

C.J. Hodgson says she drove by the crash site sometime after 10 a.m. PT, as emergency personnel were arriving.

"The tow truck and the car, their hoods were smashed in, all the airbags were still inflated in the car," she told CBC News.

"The front of the bus was smashed or ripped off, I'm not really sure, but wide open. You could see into the bus."

Traffic is backed up along the scene of a tour bus crash on the Coquihalla Highway south of Merritt, B.C. on Saturday. (VSA Maintenance)

Hodgson says she could see a handful of people looking over an embankment and others just standing on the highway.

"It's scary, especially with the people looking over the edge," said Hodgson. "It's a big drop. If they're looking for something other than their belongings, that's scary."

She said the crash appeared recent and there was only one police cruiser there at the time. But she later saw about five ambulances rushing toward the scene, she said.​

The highway is closed two kilometres south of Exit 250 at Larson Hill.

DriveBC reports the northbound lane is completely closed.

The southbound lane has been reduced to single lane traffic.

Hwy. 1 is available as a detour.

Last August, a B.C. tour bus crashed about 50 km away on the same highway injuring 43 people, five of them critically.​