Occupational Health and Safety investigators met with officials from IKO Industries just one day after a huge fire ripped through the roofing manufacturing company destroying the building and materials inside.

Emergency crews were called out just after 10:00 a.m. Tuesday, after black smoke was spotted pouring from the roof of IKO Industries, located at 1600 43 Ave. S.E.

Investigators say a building containing shingles and roofing materials caught fire and smoke from the blaze could be seen for several kilometres.

Firefighters remained at the site through the day and overnight, extinguishing several hot spots that flared up in the wreckage of the building.

Crews are carefully tearing the compromised structure apart to make sure the fire has been extinguished.

Authorities say it’s a tricky situation.

“With the walls weakened and bulging out, the movement of the cars will sent vibrations through the ground which could cause the building itself to collapse. We have to do it carefully,” says Acting Battalion Chief Edward Cornez, with the Calgary Fire Department.

More than 60 people who work at IKO were able to get out safely and no one was injured in the fire.

A number of other surrounding businesses were also evacuated but were able to return later in the day.

Carol Henke, public information officer with the Calgary Fire Department, says that crews are prioritizing hot spots in the building. Once those are out, the investigators will be able to enter the structure to determine the cause.

"They're not going inside the building because, as you can see, it's destroyed and in danger of collapsing so we don't want to put our crews at risk."

Records show that IKO has had workplace safety concerns for many years.

It's lost time claim ratio has risen sharply since 2007, and is over double the industry average.

Mayor Naheed Nenshi also expressed concern about the situation.

"Once we've got this done and have an opportunity to do an investigation into the cause, I'd be very surprised if the fire department investigation doesn't also ask the question - why have we had fires at this place before?"

Henke adds that once the initial investigation is complete, the results from that will help guide future investigations of the facility.