Windsor Police say the blaze that destroyed a Dollarama in East Windsor was intentionally set.
Police do not have a suspect at this time.
The overall investigation is not over by any means, said Windsor Fire and Rescue chief fire prevention officer Lee Tome.
Ontario's fire marshal has finished the on-site investigation of a massive fire that destroyed a Dollarama on Windsor's east side Monday.
Tome said investigators have narrowed the origin of the fire down to a shelf, four feet off the ground in an aisle in the southeast corner of the store.
Tome said a "conservative" damage estimate is $4 million.
"We’re fairly comfortable saying $4 million and going up from there," Tome said.
Tome told CBC News the building was not equipped with sprinklers, but they weren't required in 1987 when the building was constructed.
"Would we like to see sprinklers? Absolutely," Tome said. "It would have given us a better opportunity to knock that fire down."
Firefighters did contain the flames to the Dollarama, but weren't able to save the business. Several other businesses in the plaza were damaged by smoke and water.
For a before and after view of the Dollarama fire, grab hold of the arrow handles in the centre of the picture below and drag your mouse left or right.