CRANBROOK, B.C. – A helicopter plunged to the ground and burst into flames in a residential neighborhood on Tuesday, killing the three people aboard and one person on the ground, officials said.

The aircraft flew over central Cranbrook for a few minutes before plummeting, striking and dragging a passer-by as it came down, according to Elmer Bautz, who said he witnessed the crash. The “pedestrian was walking on the street across from me,” Bautz said.

The Bell 206 Jet Ranger left a trail of flames and wreckage as it skidded for several yards along a street in Cranbrook, 500 miles east of Vancouver.

Bill Yearwood, a spokesman for Canada’s Transportation Safety Board, said the pilot, two passengers in the helicopter and a pedestrian died in the crash. He said investigators were trying to determine the cause of the crash.

Officials said the helicopter had been hired by BC Hydro, a provincial power company, and was ferrying two employees to a work site.

Bautz said several people living nearby tried to help pull people from the wreckage.

The helicopter was operated by Bighorn Helicopters Inc., based in Cranbrook.

A spokesman for the company said he couldn’t comment on the crash while the Transportation Safety Board investigates.

The Royal Canadian Mounted Police said the helicopter was being flown by one of the company’s senior pilots.

No names were immediately released.