A probe continues following a fire Saturday night at a Giant Tiger Express at 1085 Wellington, in Mechanicsville.

"It was really dark, like a dark smoke but we don't know what caused it to begin with," said a GT Express staff member. "I just came out of the basement just about 15 minutes before because I was working in the basement to come on cash."

Several employees were in the store when the blaze broke out in the basement around 5:30 p.m. Everyone escaped uninjured, says owner John Ferguson, and most of the fire and smoke damage was contained to the basement.

Ladder trucks arrived on scene shortly after the initial call. Investigators from the Ottawa fire department remain and temporarily closed the road between Melrose and Sherbrooke avenues.

No cause has yet been identified.

It was the second fire in two years for the store, which had a holiday electrical fire on Dec. 23, 2007 that damaged one-third of the building and closed the store for three months. Damages at that time totalled between $700,000 and $800,000.

Upon re-opening, the store expanded its grocery and deli lines in an effort to keep urban shoppers in the core.

With a report from CTV Ottawa's Stefan Keyes