B.C. safety regulator says workers disabled ammonia detectors for monster truck rally

CTV News

11-07-2025

The Weekend Warrior monster truck at a Motorsport Spectacular event at the Canada Life Centre in Winnipeg. (Jamie Dowsett/CTV News Winnipeg)
Municipal workers in Cranbrook, B.C., were instructed to disable ammonia detection alarms inside a city arena during a monster truck rally earlier this year – constituting just one of several serious safety infractions that occurred over the course of the two-day event, according to the provincial workplace regulator.
WorkSafeBC has fined the municipality $175,783.78 for multiple 'high-risk violations' of the province's workplace health and safety standards in the wake of the February motocross event at the city-owned Western Financial Place arena.
The City of Cranbrook says it 'takes these allegations seriously' but is appealing the penalty.
Carbon monoxide exposure
A WorkSafeBC inspection report, prepared in the weeks following the event, said 10 city workers were on shift for each of the three motorsports shows held over two days, with more staff involved in the event's setup and teardown.
During the shows, which featured monster trucks and dirt bikes performing stunts before thousands of spectators, carbon monoxide levels inside the arena reached double the acceptable short-term exposure limit, and eight times the acceptable long-term limit, according to the report, though it is not known how long those elevated levels were sustained.
The arena's ventilation system had been adapted to try to prevent a buildup of vehicle exhaust fumes, however the system failed and was shut down due to cold weather during the first event, the inspector determined.
As a result, gas detection systems inside the area showed elevated levels of not only carbon monoxide, but carbon dioxide and nitrogen dioxide, as well, the report said.
'Silencing the alarm'
A health and safety representative from the city told the WorkSafeBC inspector the city was aware that a plan to control exposure to carbon monoxide was required, 'however one was not developed prior to the event,' according to the agency.
When the arena's ammonia detection system, designed to alert staff to any leaks of the potentially deadly gas, was triggered by the exhaust fumes, staff were reportedly told to deactivate the alarms.
'Upper management told workers to contact the manufacturer of the ammonia detection system to assist in silencing the alarm,' the inspection report said.
'The workers were instructed by the manufacturer on how to place the system into 'test mode,' which temporarily disables the alarm system.'
The report goes on to state that 'workers were potentially exposed to ammonia' as a result of this action.
'Ammonia is a toxic and potentially lethal gas that poses serious health risks, including respiratory issues, irritation to the eyes and throat, and, in high concentrations, can lead to severe lung damage or even death,' the inspection report said.
'Fully aware of the risk'
A 2018 ammonia leak at an arena in the nearby community of Fernie killed three men after an alarm was silenced while they performed work on the facility's cooling system.
The WorkSafeBC report said arena employees 'were upset with how management responded to their health concerns' during a meeting following the event. One employee, who spoke with CTV News on the condition they not be named, said the memory of the fatal Fernie ammonia leak was still top of mind.
The City of Cranbrook did not respond to questions about the safety report Friday.
'This employer has the resources, expertise, and obligation to anticipate risks and put preventative measures in place,' the WorkSafeBC report said. 'The employer should have been fully aware of the risk posed by engine exhaust emissions during an indoor motocross event.'
Dirt may have been contaminated
The provincial workplace safety agency also determined that the dirt used for the motorsports track in the arena was taken from the grounds of a wastewater treatment plant without first being tested for contamination from harmful substances.
In a statement Saturday, the city contended the dirt was clean fill taken from a local road construction project and temporarily stored at the wastewater treatment facility.
The WorkSafeBC report found the dirt was stored at the wastewater plant for 12 months prior to the event, and 'may have been contaminated with harmful bacteria, fungi, or chemicals that could pose risks if inhaled or contacted by workers' as a result.
'The equipment used during the event would have stirred up dust from the track to generate airborne particles, leading to exposure to biological agents and chemical hazards,' the report said.
'Exposure to dirt that has been stored at a wastewater treatment plant and may be contaminated poses significant risks to health. The soil could also be contaminated with hazardous pathogens, chemicals, or heavy metals, which can lead to serious illnesses, infections, or long-term health problems,' the report continued.
'Workers were required to truck large quantities of this dirt into the arena and spread it out into the desired track using mobile equipment. Workers were not required to wear specialized PPE (personal protective equipment). Many workers came into direct contact with the dirt and were at a very high risk of inhaling the dust.'
Fine calculated by payroll
The Motorsport Spectacular event was held over two days on Feb. 14 and Feb. 15, featuring monster trucks, mini monster trucks and freestyle motocross, according to a city announcement promoting the event.
Tickets for the event were sold directly through the city's website and at the box office for Western Financial Place, which is owned and operated by the municipality.
The WorkSafeBC fine of $175,783.78 was calculated at approximately one per cent of the city's annual payroll, according to the safety regulator.