CHICAGO (CBS) — The Christmas weekend had a tragic start in Gary, Indiana, as three children died, and two adults were injured in a fire in an apartment building late Friday night.

When firefighters arrived at the Oak Knoll Renaissance Apartments at 4200 W 23rd Ct around 11:30 p.m., an apartment was fully engulfed in flames. Two adults who had been inside the apartment escaped, but three children did not make it out.

It took crews more than two hours to extinguish the blaze. Afterward, firefighters found two children in their beds inside, and a third on the stairway on the second floor.

It was a devastating loss for family, friends, and firefighters.

“They couldn’t even stand the sight, the scene of it. One of the firefighters collapsed. They had to get a firefighter and a captain oxygen tanks, because they couldn’t even take it. The smoke and the fire, they couldn’t take it. They couldn’t even take the scene of the kids. It was just terrible. All you seen was just flames coming out the window,” neighbor Diamond Childress said.

The Lake County Coroner’s office said the children were a 2-year-old girl whose name has not been released, 4-year-old Alaya Pickens, and 5-year-old Jayden Mitchell.

A woman, possibly the children’s mother, apparently jumped from a second-floor window to escape the blaze. She was hospitalized Saturday morning with non-life-threatening burn injuries. A second adult also was injured in the fire.

Saturday morning and afternoon, neighbors came together and placed stuffed animals at the base of a tree outside the home.

Neighbor Rick Dungy said he was glad his daughter was asleep at the time of the fire, and didn’t see what happened. He said the fire was already raging before firefighters arrived.

“It was just a sight you couldn’t imagine this close to your own. My daughter could look out the windows and see this. All I could do was kind of keep her away, because she plays with the kids. So it was really not a good thing, not at this time of they year,” he said.

Fire officials said the fire started in the living room on the first floor, but the cause of the fire has not yet been determined.

Watch & Listen LIVE