Sunridge Mall in northeast Calgary was evacuated after suspects used tear gas during an armed robbery at Paris Jewellers on Saturday at 1:30 p.m., according to police.
Tear gas got into the vents, prompting the whole mall to be evacuated.
Police said the chemical went through the mall quickly, causing a “hectic scene” due to how many people were affected.
The Calgary Fire Department said at least 20 people were treated after being affected by the chemical.
The CFD said it used high-volume fans to clear out the HVAC system, noting that the department and police officers would be on scene for several hours.
Officers are looking for three suspects.
Two male suspects robbed the store and got away with “some merchandise,” police said, adding they were not able to provide an estimate of its value.
“During the robbery, the men threatened jewellery store staff with firearms,” police said in a news release.
The first suspect wore a Puma hoodie, blue jeans, white gloves and a surgical mask, and carried a green shopping bag.
The second suspect was wearing a black motorcycle helmet and black gloves. He had a black duffle bag.
When they left the mall, they got away in a stolen, beige Volkswagen SUV driven by a female with pink hair, the third suspect.
Sunridge Mall decided to close for the rest of the day.
Police are asking anyone with information to contact them at 403-266-1234. Tips can also be submitted anonymously through Crime Stoppers.