Teenagers onboard a small school bus involved in a fatal collision near Summerland, B.C. Tuesday evening say they weren't wearing seatbelts at the time of the crash.

Investigators believe that a red sedan driven by a 46-year-old Oliver man crossed the centre line on Highway 97 and smashed into the bus, which was carrying 14 students. The impact pushed the bus into a third vehicle.

The driver of the red sedan died at the scene. The pregnant teacher driving the bus, nine student passengers and the driver of the third car were all injured in the crash.

A 17-year-old girl had to be airlifted to Kelowna General Hospital, where she remains, while the other injured people have all been treated and released.

Lisa Churko, one of the students injured in the collision, told CTV News that even though the bus driver was wearing her seatbelt, the teenagers were not.

"Everyone was in the air and then I hit the top of the bus and I covered my head and then I fell down. When I opened my eyes again, there was smoke everywhere and I was on top of everyone and they were all screaming," she said.

One of Churko's friends was knocked unconscious after her head struck a hand rail.

"She was hanging over it, and so we all thought she was just dead," she said.

The vehicles involved in the crash were all inspected on Wednesday, and police say the evidence seems to confirm that the students weren't wearing their seatbelts, in contravention of the law.

"Seatbelt usage is mandatory if the vehicle is so equipped. In this case here, this bus does come equipped with seatbelts for all occupants," RCMP Cpl. Dan Moskaluk said.

The occupants of the third vehicle, John Watt and Elaine Tanner, say it's surprising no one else died in the crash.

"My first thought, in a flash of an instant, is, ‘Oh my god, whoever is in that red car is going to die, and that bus driver is going to die,'" Tanner said.

"We figured we were going to be killed," Watt added.

Despite being shaken up in the collision, Watt tried to help the driver of the red car, but soon realized there was nothing anyone could do.

"The impact of that really upset me that I had to witness this poor young fellow's death, but to his family: He didn't feel any pain. It happened very quick and very suddenly," he said.

Investigators haven't pinpointed a cause for the crash, but they're suggesting that pooling of rain on the highway may have been a factor.

With a report from CTV British Columbia's Kent Molgat