A stubborn fire continued to smolder Tuesday morning, a full day after Toronto firefighters rushed to the west-end storage facility to begin battling the blaze.

Crews continued to douse hot spots inside the storage building at 97 Pelham Ave., near Dupont and Dundas Streets, trying to end the fire that has gutted the building and destroyed nearly everything inside.

The extensive battle began at 6:15 a.m. Monday and has continued uninterrupted through the evening. At one point the blaze was considered a five-alarm fire and fire crews have held a defensive position outside the building.

Twenty-four hours after they first descended on the building, fire crews are still hesitant to enter the building over fears that the fire and water has damaged and weakened the structure.

A near-tragedy was averted Monday afternoon when a firefighter combing through the labyrinth of hallways and locked storage rooms fell through a weakened third-floor building and landed one storey below.

Toronto Fire Services say the crew member escaped the incident without injury and was taken to hospital as a precaution.

On Monday evening, the fire reached the roof of the building, shooting flames into the sky.

Toronto Fire Services say that firefighters have had trouble travelling through the high security storage facility and have found pockets of "deep seated burning of debris."

"You've got everything there from tires, to appliances, to chairs, furniture, that's what's burning," said division Commander Mike McCoy said Monday.

Nearby St. Josaphat Catholic School was closed by the fire Monday and the Toronto Catholic District School Board says it will remain closed on Tuesday.

Staff and students are being moved to St. Luigi Catholic School for the day.

The initial damage estimate has been pegged at $1 million.