One man’s split-second decision may have saved two people from a Gladstone Avenue fire that sent two people to hospital with critical injuries Tuesday morning.

Firefighters were called to 244 Gladstone Ave., a rooming house on Gladstone just north of Dundas Avenue West, before 8 a.m.

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John Maki awoke to the sound of his neighbours screaming for help. He ran to their window and helped two people escape from the fire with a ladder. Police are calling him a hero. (Trevor Dunn/CBC)

They arrived to find the entire building filled with smoke.

Janice Arsenault awoke at around 7:30 a.m. to the sound of her downstairs neighbour screaming.

"I tried to open my door to see if I could exit that way and it was just a wall of smoke and it was really, really hot," she said.

With smoke flooding into her room, she went to her window and screamed for help.

John Maki, who was sleeping in his apartment across the laneway, heard her screams and ran to help.

“Basically I just woke up to somebody screaming ‘help’ and my instincts kicked in to just run out of the house," he told CBC News. "I knew I had a ladder down here. So I just brought it out and propped it up for them so they could get out.”

Arsenault and a man escaped using the ladder Maki had set up. Both said without Maki's ladder they would have had to jump.

At least five people managed to get out of the building. Some, including a blind woman, had to make their escape through black smoke.

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One man remains in hospital after a fire broke out at this rooming house at 244 Gladstone Ave. last October. The property owner has been hit with more than $350,000 in fines. (Trevor Dunn/CBC)

Two people, a man and woman both believed to be in their 50s, were unable to escape on their own. Firefighters found them unconscious on the building's third floor.

The man was taken to hospital suffering from serious burns. The woman was taken to hospital without vital signs.

Both are listed in critical condition.

The fire was extinguished just after 8 a.m.

It’s believed the fire started in a second-floor kitchen.

The Office of the Fire Marshal is now investigating.

With files from CBC's Trevor Dunn