A man, believed to be in his 30's and from Kitchener, has been killed in a partial structure collapse at the Sheridan Centre Mall in Mississauga.
The area under construction is to be the new Target store at the mall.
Mississauga Fire officials confirmed the news just before 1 o'clock on Monday afternoon.
The man became trapped underthe piles of steel just after 11:30 a.m.
Other workers at the site said the man killed was laying down the roof deck when steel joists collapsed underneath him.
There is no indication as to what led to the collapse, but the Ministry of Labour and Peel Police have taken over the investigation.
The building was still just a steel skeleton, and at no point were shoppers in danger.
The man's name has not been released.