Residents of an apartment building downwind from a fire at the Hydro One Station near Highway 401 and the 427 were evacuated from their building Friday night. 

People living at 44 Longbourne Drive were told to leave their homes as the four-alarm fire at the company's Richview transformer continues to churn out thick black smoke

The TTC sent buses to help evacuate residents.

Bus users were warned of a slowed service in parts of the city as a result.

The fire, which briefly shut down traffic on Highway 401 at rush hour and shut down power at Pearson International Airport, was fought by about 30 fire units and Hydro One's own emergency teams.

Reports suggest the flames slowly dwinded after firefighters requested that public works turn-up the water pressure.

No injuries have been reported.

The fire broke out at 3:49 p.m. at the 230-kilovolt line distribution centre which feeds power to hundreds of thousands of people. It is considered one of the larger sites in the GTA.

It is estimated that Toronto lost about one per cent of its electricity, or 32 megawatts of power, when the failure occurred.

The city usually uses about 3,500 megawatts during peak afternoon times.

The power went out at Pearson International Airport's Terminal 3, but the facility used a generator in the interim. Flights aren't being affected by the situation.

As a result of the fire there was an immediate loss of voltage in the West End to compensate for the instant loss of power meaning many would have either lsot power or experienced ‘power bumps'.

However, the independent Electricity System Operator(IESO) said there is no problem re-routing electricity to any other parts of the GTA

The Richview Transformer Station was undergoing millions of dollars worth of upgrades and capital investments. Hydro One documents show $15 million was to be spent on air blast circuit breakers and another $9 million on transformer replacement in 2011 and 2012.