A family of four is now recovering in hospital after their southwest Calgary townhouse caught fire early Thursday morning.

Crews were called to a townhouse complex in the 4900 block of 35 Avenue S.W. for reports of a fire at about 1:00 a.m.

Smoke was pouring from the front door of one of the units when crews arrived and four people were waiting outside.

All suffered from smoke inhalation and were taken to hospital.

Crews were able to knock down the blaze and contain it to one room of the home.

Officials say that the rest of the structure suffered extensive smoke damage and that there were no smoke alarms in the home.

"When our crews were conducting the search for additional occupants, it became very apparent there was no smoke alarms at all in this residence," said CFD Battalion Chief Allan Ball. "When we were ventilating the adjacent unit, we found there were no working smoke alarms in that unit as well. Obviously, it's a huge concern for Calgary Fire. This could have been a lot worse."

Officials say people need to ensure they have working smoke detectors in their homes to alert them in the event of a fire.

"Obviously, they weren't alerted to this fire by a working smoke alarm. I don't think it's a stretch that that's why they're suffering from smoke inhalation."

Neighbours say some of the homes in the area are close together and they were surprised to learn smoke alarms were not found in the home.

"There was a fire in the same property about six or seven years ago," said Carol Brown. "It's really frightening. There's lots of families and small children. I can't imagine having a home without working smoke detectors. There's lots of properties close together and one fire could take down multiple homes."

The fire department says crews will re-visit the area on Thursday evening to install and test smoke alarms in each unit of the complex and to pass along fire prevention information.