WATCH: Woman rescued from apartment fire arrested for arson

A woman rescued from a narrow ledge outside their third floor apartment as a fire grew behind her has been arrested on suspicion of arson.

The fire call went out from a highrise at 490 Sherbourne St before 8:30 a.m. Tuesday. Seeing smoke pouring out of the building, firefighters on scene requested more help.

Toronto Police constable Victor Kwong says the woman has not been charged but investigators believe the fire was intentionally set. Kwong could not share where or how the fire is thought to have been lit.

Toronto Fire Captain. Adrian Ratushniak says firefighters' first priority was to safely get the tenant down and that time was of the essence.

"We don't know how hot it is, how long they've been out there, and for how long they can actually hold on...certainly it's an urgent situation for us," Ratushniak tells NEWSTALK 1010

The woman was safely retrieved with the use of a pumper truck ladder. They were treated on scene by paramedics. The tenant's condition is unknown.

It is also unknown whether or not the fire originated in the woman's unit. Ratushniak says even if she were not close to the fire, the smoke billowing through the apartment could have lead to suffocation and is likely the reason why she made a desperate attempt to escape.

Ratushniak says while this kind of dramatic scenario does not happen often in Toronto, firefighters are well-prepared for an intense situation like this one in the first few days in their training. Firefighters are also updated on a constant basis should better rescue methods come about.

The fire has been extinguished after 21 firetrucks were on scene.

The Ontario Fire Marshal has been called in to investigate.

Lauren Wininger/NEWSTALK 1010, with files from Siobhan Morris