The Transportation Safety Board of Canada is warning about the risks of fires going unnoticed on locomotives and setting wildfires, citing dozens of on-board blazes in a report into an incident two years ago in southeast British Columbia.

The board says there have been at least 21 more on-board fires involving “remote” locomotives in the middle or at the end of a train since the incident, with 34 occurring in the 10 years before.

The board says a mechanical failure on a locomotive in the middle of a Canadian Pacific freight train caused fire and embers to shoot out of its exhaust, setting a wildfire near the tiny community of Caithness in July 2021.

It says the on-board fire wasn’t detected until it was seen by the crew of a passing train, while the trackside fire grew to 1.2 hectares before it was put out by local volunteers and the BC Wildfire Service.

The board says freight locomotives aren’t equipped with real-time sensors to detect fires, and it’s concerned that remote monitoring systems aren’t in place.

Canadian Pacific is said in the report to have responded to the Caithness fire by requiring locomotives in areas where the fire danger is extreme to have been inspected in the previous 15 days, as well as enhancing “vegetation control” near train tracks.

“Early detection of locomotive fires would allow for prompt intervention to prevent the spread of these fires,” the board said in a statement.

“Until technologies are implemented to detect fires on remotely located locomotives, there is a risk that those fires will remain undetected using existing methods, which could lead to trackside fires.”

Fires sparked by trains have been a controversial subject in B.C., with some residents of Lytton blaming a train for the wildfire that largely destroyed the Interior village in June 2021, although the cause remains undetermined.