The Transportation Safety Board has released its first update on an investigation into a small plane crash that killed three people in northwestern B.C. over the weekend.

BC Wildfire Service had contracted four people to conduct an aerial survey of damage caused by a 2018 wildfire near Smithers. The crew was flying north of the town when their Cessna 182 went down Saturday morning.

It is not yet known what caused the crash, but on Wednesday, the TSB said the plane had taken off from Burns Lake.

"About 3 hours into the flight, the pilot transmitted a Mayday before communication was lost," the initial report says.

The wreckage was found about 50 nautical miles north of Smithers, near the Babine River.

Three people died in the crash. One is believed to be the pilot, and has not yet been publicly identified.

The other two fatalities were Amir Sedghi and Lorne Borgal.

Sedghi was a 26-year-old resident of North Vancouver who worked for Precision Vectors Aerial Inc. as a data analyst. Borgal was his boss, the CEO of the company and a ski patrol volunteer, as well as a husband, father and grandfather.

The fourth person on the plane was conscious when he was found and is expected to recover. The man, who works for a U.S. company, was long-lined from the crash site then flown to a Vancouver hospital.

The TSB investigation is ongoing, and the BC Coroners Service is also looking into the crash.
 

Map of plane crash site