Survivors of an early-morning 36-unit apartment fire in Sutton, Ont., are crediting a young man who risked his safety to help save their lives.

One woman gave 21-year-old James Slatcher a thank-you hug on Monday, saying he was the hero who warned her about the blaze.

"He actually saved our lives by coming and knocking on the door and telling us," said fire victim Julie Grainger.

The fire is estimated to have started at about 3 a.m. Monday. The structure is located at 21028 Dalton Rd. in the town on the south shore of Lake Simcoe.

When he discovered the fire, Slatcher said he banged on a few doors. When the fire alarm didn't automatically go off, he manually triggered it and then resumed going door to door in his building, waking up sleeping tenants.

"They eventually came to the door. And they had a surprised look on their face like they didn't know what was going on. I told them their house was on fire," he told CTV Toronto.

Slatcher said he asked one lady if she needed help and ended up carrying children down the stairs and outside to safety.

Eleven people were in that particular apartment, including seven children under the age of six.

York Regional Police said no people were injured in the blaze, but added the outcome could have been very different without Slatcher's help.

Some people did report losing pets to the flames.

No damage estimate is immediately available, but parts of the complex were completely gutted by the fire. York police said the Ontario Fire Marshal's office is still at the scene with police investigators.

About 100 people will be sleeping in shelters or with friends and family Monday night as a result of the blaze.

With a report from CTV Toronto's Austin Delaney