One man was seriously injured after jumping out of a third-storey window to avoid heavy smoke caused by a fire in an apartment building in the Overbrook neighbourhood on Friday morning, firefighters say.

Fire 725 Bernard Street Overbrook rescue firefighters April 11 2014

The fire was brought under control at about 7:15 a.m. (Leonard Poole)

The fire broke out in a third-storey bachelor unit at 725 Bernard St., near St. Laurent Boulevard and Coventry Road at about 6:45 a.m.

The building has about 100 units. The fire was quickly classified as a second-alarm blaze.

When firefighters arrived at the building, some residents were trying to get fresh air by sticking their heads out of windows. Six of them were rescued by firefighters using ladders, said fire department spokesman Marc Messier.

One man had jumped out of his third-storey window to avoid the heavy smoke. He suffered a broken leg as well as smoke inhalation, and was taken to hospital in serious condition for treatment, paramedics said.

Another man suffered hip and back injuries as well as smoke inhalation, paramedics said, adding that he also may have jumped from an unknown height. He was in serious condition.

Ottawa fire 725 Bernard Street rescue April 11 2014

Ottawa fire Chief John deHooge tweeted this picture of firefighters responding to a blaze at 725 Bernard St. in Overbrook on Friday morning. (Ottawa fire Chief John deHooge)

Three other people were taken to hospital to be treated for smoke inhalation. They were listed in serious but stable condition.

The fire is believed to have started in the cooking area of a third-storey unit, which was destroyed. A dead cat was found in the unit.

The third-floor hallways and units have extensive smoke and water damage, Messier said, and residents there have not been allowed back inside. The Salvation Army and Red Cross were on scene to assist affected residents.

Meanwhile, residents on the first and second floors have returned to their homes.

Total damage is estimated at about $200,000. The fire was under control at about 7:15 a.m.