Halifax Fire says it was construction materials that caught on fire at a high rise in downtown Halifax that blanketed the area with heavy black smoke.

Acting District Chief Joe Fulton says it was about 1:30 p.m., Wednesday, when they got the call and arrived to a heavy blaze on the left side of a building on Cogswell Street.

“When crews arrived on the front side of the building, heavy smoke and fire coming from the left side, they quickly deployed a line. That actually protected the adjacent homes and structures as well,” says Fulton.

He says it’s not clear at this point what exactly caused the fire, but it might have been Styrofoam because materials like that are petroleum based like that, can cause the heavy smoke.

“The smoke looks really bad. It did mitigate through the structure but no actual fire damage within the structure,” adds Fulton.

A few construction workers were also in the building but on injuries reported.

However, seeing a very large cloud of dark smoke was disconcerting to community members.

Ashley Wong tells us she was eating lunch at a restaurant on the Dartmouth waterfront when she noticed the smoke rise out of the buildings along the Halifax Harbour.

“It just kept going and going until the whole harbor was engulfed in smoke,” says Wong.

She was immediately worried.

“I could hear the sirens were immediate, I went outside to film, get some shots of it and there were a lot of concerned people around me calling their loved ones to make sure people were okay,” adds Wong.

She says only about 15 minutes later the smoke started to dissipate.

The fire is under investigation.