The Calgary Fire Department is at the scene of a fire in the southeast that has destroyed at least one home and damaged several others early Sunday morning.

Crews were initially notified about the incident at about 4:20 a.m. when several 911 calls were made by residents in the community of Douglas Glen.

The callers also reported hearing an explosion in the area of Douglas Glen Close S.E.

When firefighters arrived at the scene, they found a home that was fully involved in flames that were beginning to spread to a second house.

A second alarm was called to bring in more resources due to the size of the fire as firefighters began an aggressive attack on the source home and worked to keep the blaze from spreading further.

Due to structural concerns in the source home, firefighters were not able to enter it and search for any occupants. As a result, it is unclear if anyone was hurt as a result of the fire.

Five other homes were evacuated as a result and traffic on Douglas Glen Boulevard is being affected as a result of the firefighting efforts.

One neighbouring home sustained severe damage while a number of other adjacent homes had melted siding and broken windows as a result of the radiant heat.

Calgary Transit buses were brought in to house the displaced residents, but a number of families were allowed to return to their homes by 7:00 a.m.

Spencer Stevens, who lives in the area, was awoken by the sound of the explosion and saw the house on fire.

"I looked outside and the entire house was entirely engulfed in flames. There wasn't too much we could do about it. We just got our stuff together and got out, just in case."

He says the fire came on so suddenly that he wonders about the safety of anyone inside the home that burst into flames.

"I'm hoping that they did; I've heard good news about that. Everybody was just making sure that everybody was out of their house and knew what was going on. It's not everyday that a house explodes."

Diane Bender said she heard a bang and a number of items fell off her wall when the explosion occurred.

"I literally felt I was having a heart attack at that point in time. It also woke my husband up. We checked to see if something had hit the house and we came outside and noticed everybody outside. We came out immediately to find out the house four doors down was on fire."

When she saw the fire, she was immediately concerned about the residents but was also worried about losing her own home.

"We're always worried about losing that. We're retirement age and that's the scariest thing possible. But everyone was safe, the fire department was out here fast and the police are doing a great job so we're in good hands."

Fire officials are still at the scene to determine the cause of the fire and watch for any hot spots.

CFD District Chief Innes Fraser says crews were able to arrive very quickly and put the fire out, but the house of origin is a total loss.

"There were homes that were damaged by the fire and the debris field. We have gone and checked all the other homes in terms of livability. The air quality is good and they were able to get back into their homes with the exception of the one home on the side of the source house."

He says it's likely the home next to the one that exploded will have to come down too.

At this point in time, Fraser says there is no indication that there was anyone inside the home, but further investigation will have to be done.

Any witnesses who have video, photos or other information are encouraged to email piofire@calgary.ca.