Saskatoon firefighters battled an apartment building fire on the east side early this morning that has left at least 16 people homeless. 

Fire investigators determined later Friday the blaze at 704 Hilliard Street was caused by improper disposal of smoking materials. 

The fire broke out in the three-storey building early Friday morning. When fire crews arrived, flames were shooting from the roof of the building and reinforcements were quickly called in. 

"Fire alarms were going off very loudly at 2 a.m. exactly, just about on the dot," resident Karen Thompson said. "And they woke me up, got me out of bed. I was startled obviously."

Thompson lives on the ground floor and went out into the hallway to check out the situation. She didn't see or smell any smoke and thought it was a prank. 

'I looked up at the building at the top and the flames were probably six, seven feet high already so I knew it was quite serious and at that point we only had minutes to get out.'- Karen Thompson, resident

She went back into her apartment and opened the blinds. She then saw neighbour running to and from his car.

"And at that point, I realized there must be a fire," she said. "I ran out the building to talk to him for a second and he said 'it's a fire'. I think that's what he said to me, I mean I was so shocked".

She ran back in to get her laptop.

"And at that point, I looked up at the building at the top and the flames were probably six, seven-feet high already, so I knew it was quite serious, and at that point we only had minutes to get out."

Hilliard Fire 1

A firefighter with Ladder 19 mops up after an apartment building fire early Friday morning. (Dan Zakreski/CBC)

 The department called in eight trucks and 32 firefighters. Crews were able to get the fire under control in less than an hour, but not before it gutted four top-floor suites and left eight others badly damaged by water. ​

 Fire crews went into the building to search and clear out about 100 people. At this time, firefighters believe that everyone made it out of the 48-suite building.

The fire was so intense that firefighters set up a perimeter outside the building, rather than battling it from the inside.

No cause has been determined. The fire caused about $2 million in damage.

People living in the building were initially given shelter in city buses called to the scene. They were then moved to another location and have since dispersed to stay with family and friends. There are no reports of injuries. 

Erin Torgunrud who lives in the apartment block had to find a place to spend the night.

"We stayed over at a neighbour's house that let us into her house for the night," she said. "And then we came over after everybody woke up to try to assess stuff and we don't know anything."