Transformer explosion in a downtown Montreal building injures two electricians during outage

What happened

On 13 June 2018, an electrical transformer exploded in a building at the corner of de Bleury and Sainte-Catherine streets in downtown Montreal, injuring two electricians. Police said both men suffered burns to their upper bodies and were in critical condition. Hydro-Québec said they had been working downtown when power failed late that morning and decided to look at the problem themselves. Why the transformer exploded was not clear, and the utility said it was running an audit.

The utility blamed the wider outage, which left about 40,000 homes and businesses in Montreal and on the South Shore without power, on a large truck that severed a power line in Brossard. Supply was cut automatically as a precaution and was restored to most customers by 3 p.m.

Contributing factors

The cause of the explosion was not reported. Hydro-Québec said the two electricians decided to investigate the outage themselves. The utility attributed the outage to a severed power line in Brossard, not to the explosion.

Lessons learned

1. Do not enter a building electrical room to investigate a utility outage without the network operator and a confirmed isolation.
2. Keep the reported cause of an outage separate from a later explosion until an audit establishes any link.
3. Treat transformers as hazardous during an unplanned outage and keep people clear until the equipment is made safe.

Source

cbc.ca