A small plane crashed and burst into flames on a road near Vancouver's International Airport on Thursday, sending nine people to hospital.

Five of the victims were taken to Vancouver General Hospital in critical condition, while the rest were being treated at Richmond General Hospital with less severe injuries, B.C. Ambulance Service spokeswoman Kelsie Carwithen told The Canadian Press.

The nine-passenger Beechcraft King Air 100 had been travelling to Kelowna when it turned back to Vancouver for unknown reasons. It hit the ground as it approached one of the airport's runways just after 4 p.m.

Firefighters and paramedics quickly arrived on scene. Footage of the crash site showed badly burned wreckage, with the plane's tail twisted away from its fuselage.

Airport employee Stephen Van Dolder told CTV News he approached the wreckage and saw "quite a bit of flame."

The plane was operated by Northern Thunderbird Air, based in Prince George, B.C.

Nearby resident Steve Smith was driving home with his daughter when spotted the crash.

"By the time I parked my car, there was a massive jam-up of cars. I saw people being tended to at the side of the road," he told CP.

Moments later, he watched fire trucks roll into the scene.

"I was thinking, those guys are heroes for helping them out. You must go into auto-mode. You get a knot from your stomach thinking people are hurt," he said.

"It was a very heartening response."

The Transportation Safety Board has sent investigators to the scene.

Bill Yearwood, from the TSB, said that the aircraft was about 60 kilometers northeast of the airport when the two pilots began experiencing trouble.

"The aircraft fell short of the runway and crash-landed on the road," he told CP, adding he wasn't sure what the problem was.

Northern Thunderbird Air was formed in 1971 after an amalgamation of the Thunderbird and Northern Mountain airlines.

The company has a fleet of 11 planes and 70 employees.