Background

Cyanide is used in gold mines and mills as part of the extraction process to remove gold from ore. Cyanide is highly toxic by all routes of exposure and may rapidly impair the nervous, cardiovascular and respiratory systems leading to death within minutes to hours.

There is no free oxygen in the underground, and nothing consumes oxygen faster than fire

What happened?

In Ontario in 2008, 80 underground fires were reported to the Ministry of Labour. Heavy equipment is a often a source of underground fires. Without preventive maintenance and operator training, the equipment lends itself to creating fire hazards - engine temperatures can reach 500 Celsius causing the ignition of fuels such as oil and grease. Faulty wiring and overheated components can also cause fires to ignite.