Campers near Pemberton B.C. who witnessed Saturday’s mid-air plane collision that killed four people were still reeling from their dramatic experience.

“We saw this plane falling out of the sky, half the plane, and the pilot and the unopened parachute behind him, literally 500 feet in front of our trailer,” camper Wes Karsgaard said.

“Everybody was screaming and yelling, ‘get out of your trailers, there's stuff falling out the sky!’”

No campers were injured by the falling debris at Nairn Falls Provincial Park near Pemberton, about 150 kilometres north of Vancouver.

A Cessna 150 plane collided with a glider on Saturday, each carrying a pilot and a passenger. A dog aboard the Cessna was also killed.

“We heard a big bang and a big engine kind of rev and we looked up in the sky and we saw the plane spiralling down out of the sky," Terry-Lyn Evans said.

Desire Labrance said she heard someone who was first on the scene near the fallen glider say “they’re gone, they’re gone.”

“Our first reaction was to just run and see what happened. I ran over, there was fire, crashed plane, and two people died unfortunately,” Michael Greenwood, who was camping near where the glider crashed, said.

Police have confirmed that two people in the Cessna were from 100 Mile House and the two people in glider were from Pemberton.

Rudy Rozsypalek, a well-known and experienced pilot who appeared on the Discovery Channel alongside famed British Explorer Chalie Boorman, was onboard the glider at the time of the collision.

Rozsypalek operated the Pemberton Soaring Centre.

Pemberton mayor Jordan Sturdy said news of the accident travelled quickly through the community of about 2,400 people.

"We all very much want to understand the cause of this tragedy and how a mid-air collision could take place in an area like this -- I don't understand it," he said.

The Transportation Safety Board (TSB) has taken over investigation from the RCMP and they have sent two investigators to the site to examine the wreckage and gather data.

Bill Yearwood of the TSB said neither aircraft had on-board equipment that could alert pilots of potential collisions, and added that it is too early to tell what the cause was.

"The obvious conclusion we can make is that they didn't see each other in time to avoid the collision," Yearwood said in an interview.

"In the area where these aircraft were flying, they rely solely on see-and-avoid, so our investigation will have to try and determine what safety issues or limitations led to this tragic collision and why these pilots did not see each other in time."

The TSB will conduct a full investigation and produce a public report, Yearwood said.