Around 7:30 in the morning on Sunday, a massive explosion reduced a number of businesses inside this plaza to rubble.

It sparked an equally substantial fire, heavy smoke was seen billowing towards the sky from the building which officials say is a combination of commercial and residential units.

The building is near TL Kennedy Secondary School.

Mississauga Fire Chief Tim Beckett says firefighters were forced to fight the blaze in a defensive operation.

Crews were able to rescue three people who were living in the residential units at the back of the building, a man and woman police believe are in their thirties and a four year old child.

The sheer force of the blast was felt by residents.

It shattered windows at a nearby apartment building and has affected dozens, forcing people to evacuate their homes and businesses.

Chief Beckett says those people are being housed at a reception centre until investigators say its safe for them to return home.

Crews had the difficult task of working through challenging weather conditions.