A three-alarm blaze in a Barrhaven condo building is under control, but 16 units have been gutted and up to 45 have been displaced.

Ottawa Fire says the fire broke out at 601 Chapman Mills Drive at around 8:30 a.m. Wednesday. The fire spread so quickly that it was upgraded to a three alarm blaze within ten minutes of the first 9-1-1 call. 

"Those who were at the front didn't quite understand the depth and severity until they made their way to the back," said Danielle Cardinal, a spokesperson for Ottawa Fire. "The majority of the damage is at the back and on the roof." 

Suhail Bahtti was asleep when the fire started. He said the fire alarm never went off. 

"The only thing that woke me up was the fire trucks pilling up outside," he said. "I see all these firetrucks and firefighters running."

Bahtti says he woke up to see smoke and flames in his condo.

"I had to crawl out and I'm on the upper unit, so that makes it even more scary," he said. "It's always been a nightmare for me, and to have your house on fire, especially when you are in bed, that's pretty much what happened."

Bahtti escaped unharmed, but his girlfriend was transported to hospital with smoke inhalation, but is expected to be okay.

The cause of the fire is under investigation. Residents say it is believed to have started in the basement or a first floor apartment. 

Some residents are expected to be able to return to their units tomorrow. It's unclear how long the other residents will be out. 

Ottawa Fire officials believe the fire started outside the building and spread inside.