MOUNT OLIVER (KDKA) — Heavy smoke and flames engulfed three homes in the city’s Knoxville section late Tuesday morning.

Firefighters were called to the scene of the five-alarm on Reifert Street around 11:30 a.m.

WATCH LIVE: NewsChopper 2 Over The Scene —

Smoke was seen pouring from the roof of the home where the fire initially started. Five people, including a baby, were in that house.

Two young adults got the baby outside the house and onto the roof, where the baby was tossed to someone on the ground.

Firefighters then used ladders to remove two adults and the two young adults.

The fire then spread to the homes on either side. The gray home on the left was vacant, but the white house was occupied.

All are total losses.

(Photo Credit: NewsChopper 2/KDKA)

(Photo Credit: KDKA Photojournalist Fred Williams)

(Photo Credit: NewsChopper 2/KDKA)

Alexis Bopp watched from her back porch.

“We could hear glass in the windows shattering,” Bopp told KDKA’s Brenda Waters.

“There was wood crashing. We could see the entire house in the middle was up in flames.”

Pittsburgh Fire Chief Darryl Jones says firefighters knew immediately what they were dealing with.

“We received information of people standing on a roof and the building was involved heavily and people were threatening to jump,” he said.

Three firefighters and a police officer were injured, and they are all expected to be okay.

The cause of the fire is under investigation.