Three firefighters suffered non-life-threatening injuries while battling a townhouse blaze near Dupont Street and Lansdowne Avenue on Wednesday.

One of the firefighters was taken to hospital to be treated for a leg injury that she suffered when a floor collapsed, said Division Commander Andrew Kostiuk.

The other two firefighters were treated in hospital for smoke inhalation.

The blaze broke out in the basement of a townhouse unit on Perth Avenue, north of Dupont, at about 7:50 a.m.

Kostiuk said a crew went through the door with a hose and the floor collapsed as they entered the building, sending them tumbling into the basement.

A mayday was immediately declared and the blaze was raised to a third alarm to pull more resources to the scene.

When the firefighters fell into the basement, the fire captain held onto the edge of the first floor, allowing his colleagues to climb over his back and escape, Kostiuk told CP24 reporter Karman Wong at the scene.

"We don't train for that, but they made due," he said.

Kostiuk said the fire spread into the roof but a concrete firewall prevented the flames from spreading to the neighbouring unit.

The neighbouring suite suffered some water damage, he said.

Dupont Street from Perth Avenue to Symington Avenue was closed for a period of time but has since been reopened.

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