Toronto Fire Services did steady business on Thursday, dealing with three separate highrise fires by the early afternoon.

The first call came in at 2:30 a.m., involving a single-alarm fire at a highrise condo building at 3650 Kingston Road, which is near Markham Road.

Residents say the fire was accompanied by a blast that shocked them awake.

Toronto Fire Services Captain Adrian Ratushniak told ctvtoronto.ca that the fire was in the building's hydro vault and was mostly suppressed by built-in sprinkler systems by the time firefighters got there.

But the hydro vault fire caused damage to an outdoor transformer, which ended up cutting power to the building that is home to some 600 people.

Initially, some of the residents were allowed to return home if they chose.

But by the late morning, authorities ordered all of the residents out while they inspected the damage to the building and worked to restore power.

Residents were offered temporary shelter at a local community centre.

A Toronto Hydro spokesperson told ctvtoronto.ca that power could not be restored until the building's interior damage was dealt with.

"The problem originated in the customer's electrical room panel, which caused damage to our equipment which is located outside of the building," Tanya Bruckmueller said in a brief phone interview on Thursday morning.

"So right now, we have crews there to make repairs to the transformer, but until the repairs are made in the building, we cannot restore power."

Just before 9 a.m., firefighters rushed to the scene of another fire -- this time, a two-alarm blaze on the 12th floor of a Toronto Community Housing highrise building at 285 Shuter St. Within an hour, it was under control.

There were no reported injuries.

Toronto Community Housing spokesperson Kyle Rooks told ctvtoronto.ca that the damage is estimated at $30,000 and the cause of the fire remains under investigation.

At about 1:00 p.m., firefighters were also called to a three-alarm fire at a four-storey apartment complex located at 2369 Lake Shore Blvd. near Albert Avenue.

Toronto Emergency Medical Services spokesperson Lyla Miller said three patients were taken to hospital with non-life threatening injuries.

The city has set up a reception centre for affected residents at Ourland Community Centre, 18 Ourland Ave. That is near Evans and Islington Avenues.

With files from CTV Toronto