A Cessna 150 plane and a glider collided Saturday afternoon above Nairn Falls Provincial Park, located near Pemberton about 150 kilometres north of Vancouver.
Each aircraft was carrying a pilot and passenger, and all four died, the RCMP confirmed. The names of the victims hadn't been released, though police said the glider was based out of Pemberton and the Cessna was from 100 Mile House. A dog aboard the Cessna was also killed.
Debris from the collision landed in the provincial park's campground, in some cases landing within six metres of campers, though the RCMP said there were no reports of injuries on the ground.
Bill Yearwood of the Transportation Safety Board, the federal agency that probes aviation disasters, said two investigators were sent to the crash site to interview witnesses and examine the wreckage.
It was still too early to speculate about what caused the crash, but Yearwood said neither of the aircraft had navigational equipment designed to detect possible collisions and the area is not overseen by a control tower.
He said it's clear the pilots didn't see each other; the task for investigators is to determine why.
"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."
Investigators were able to start examining the wreckage from the glider on Saturday, but they had to wait until the BC Coroners Service finished its work on the Cessna to access that wreckage, said Yearwood. The investigators were able to see the Cessna on Sunday, he said.
The safety board has decided to conduct a full investigation that will result in a public report, said Yearwood. The agency's mandate is to identify potential safety issues that may have contributed to such crashes and make recommendations to avoid similar accidents in the future.
Warren Cartwright, 42, of Vancouver was pulling into the parking lot for a scenic hike to Nairn Falls when his wife noticed something falling from the sky.
"We didn't really think much of it until we parked and there was a bunch of debris all over the parking lot and what looked like the wing of an airplane lodged into one of the trees," Cartwright said in an interview.
"At that time, there started to be quite a bit of activity."
Cartwright said, at first, he heard that a helicopter had crashed. It wasn't until some time later that he learned two aircraft had collided in the sky.
"Obviously, you're concerned about the people involved," said Cartwright, who works in the aerospace industry.
Cartwright said he was impressed with how quickly police, paramedics and other emergency workers arrived at the scene.
Pemberton's mayor, Jordan Sturdy, said he went to the scene shortly after he heard about the crash from the RCMP.
"There was certainly debris spread throughout the campground, significant heaps of debris, wings and that sort of thing, some up in trees," said Sturdy, who was also elected to the provincial legislature as a Liberal in the May 14 election.
"I think what I came away with was that this is certainly a tragic situation, but in some respects it really could have been worse."
Sturdy said one victim aboard the glider was from Pemberton, and word of his identify travelled quickly through the community of about 2,400 people.
"There seems to be some common knowledge of a local who was involved," said Sturdy.
"That individual has been a person of note in the community, a tireless advocate of the Pemberton airport and Pemberton in general."
The victim from Pemberton, who The Canadian Press was not naming because the police had yet to confirm his identity, had teenaged sons, said Sturdy.
Sturdy said the accident was already having a significant impact on his community.
"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.
"Hopefully, the TSB can be in a position to make some recommendations that we can learn from."