1969
Excavation of the Square One site begins, under the auspices of The McLaughlin Group, later to become The Mascan Group. Streetsville reeve Hazel McCallion attends the ground-breaking ceremony the middle of a wind-swept hayfield, little realizing that just a few years later her own town will be absorbed into the new city of Mississauga that has been planned around the shopping centre.
1970-72
After an intensive sales effort, four major retailers – Dominion, Sears, The Bay and Woolco – are signed to anchor the four corners of the new mall, only the second shopping centre in all of Canada, and one of the largest in the world. Another 165 smaller retailers soon join their ranks.
1973
Square One opens, causing a mammoth traffic jam on Highway 10 and Burnhamthorpe Road that lasts well into the night, as more than 160,000 people show up. Over the next few months, the mall becomes one of Southern Ontario’s touristic highlights, with busloads of visitors arriving daily from as far away as North Bay, Montreal and Buffalo.
1974
A prolonged, 22-day transit strike across the GTA marks the beginning of a fitness revolution, as hundreds of thousands are forced to walk and bike to work. Residents of the brand new city of Mississauga, inaugurated January 1st, begin to question their working reliance on Toronto. Over the next couple of decades, fewer and fewer of them will choose to commute into the metropolis over careers in the community.
1978
Square One’s marketing becomes the youngest female mall manager in Canada. At the same time, councillor Hazel McCallion is elected mayor of Mississauga. To date, 25 years later, both are still holding the same jobs.
1979
Square One wins the Energy Conservation Recognition Award for its innovative computerized temperature control system, the first ever in a Canadian mall.

The Mississauga Miracle

Just prior to midnight, Saturday, November 10th, 1979, a 106-car freight train passing the intersection of Burnhamthorpe and Mavis Roads in Mississauga flies off the rails. Sparks ignite its propane fuel cargo, setting off a series of intense explosions, one of which measures 1,500 metres high and is visible from 100 kilometres away. The resulting fire threatens to release a deadly assortment of containered chemicals, including highly toxic chlorine gas. Two hours later, early Sunday morning, the decision is made to evacuate 3,500 residents close to the derailment site, the first of 13 escalating evacuations over the next 20 hour period. Police go door-to-door, waking residents and directing them to the official emergency evacuation centre at Square One.

Close to a quarter million people are eventually displaced from the city, returning nearly a week later. There is no reported loss of life, serious injury or looting. The Mississauga Miracle, a defining moment in the young city’s life, remains to this day the largest and most peaceful mass evacuation in North American history.

1980
At their Los Angeles convention, The International Council of Shopping Centres presents a special Maxi award to Square One for its major assistance during the Mississauga Train Derailment crisis.
1984 -Hammerson Canada acquires Square One from The Mascan Group and begins a long-term cycle of expansion and renovation.
1986 -Phase One of Square One’s refit is complete with the enclosure of the Garden Court, now renamed the Centre Court, and the addition of 80 new tenants, including several Food Court franchises.
1988
Phase Two is complete, with the addition of more than one million square feet of retail space, a growth in site area to 90 acres, and an increase of parking capacity to 7,500 cars, including a new 200-car, two-level parking deck next to The Bay. Eaton’s becomes Square One’s latest tenant, bringing the nation’s four major department stores together under the same roof for the first time ever.
1997
Square One increases the parking deck at The Bay to three levels and a 400-car capacity.
1998
Hammerson Canada sells its holdings in Square One to OMERS Realty Corporation and ARCA Investments. A new three-level parkade adds more car stalls, and the Mississauga Transit bus terminal is relocated to the site’s north side.
2000
Square One’s Cityside expansion opens partially, consisting of 220,000 square feet of new retail space, 100,000 square feet of common areas, and 370,000 square feet of underground parking for 750 vehicles.
2001
Square One’s Cityside is fully open, featuring a 10-screen Cineplex Odeon, large new concept stores by Tommy Hilfiger and Parasuco Jeans, as well as the Gap and the largest Old Navy store in Ontario.
2003
Square One celebrates its 30th Anniversary. With 360 stores and services, plus the reclassification of the West Edmonton Mall as an entertainment complex, it is now arguably the largest shopping mall in Canada, at 1,600,491 square feet in retail space, 8,704 parking spaces, an average of 400,000 customer visits per week, and an average of 21 million customers per year. It is also at the heart of the city of Mississauga, a city of 650,000 people, surrounded by the Civic Centre, the Central Library, the Living Arts Centre, as well as the Playdium, the Famous Player/Imax theatres, and multiple restaurants, office towers and condominiums.

The Great Blackout

On Thursday, August 14th at approximately 4:00 PM, a huge swath of eastern North America became completely blacked out, due to cascading electrical failure set off by an Ohio-based power station.
Within one hour of the continental catastrophe, Square One was completely evacuated. The mall remained closed for a day and a half, opening Saturday morning on power voluntarily reduced by management by 40%.
Square One Operations Manager Al Cabral credits the mall’s annual full-scale fire drills for the efficiency of its evacuation process, plus the spirit of its retail tenants and customers for their cheerful cooperation in the midst of this disaster.

2004-2007

Square One Completes $33 Million Dollar Renovation!

Square One Shopping Centre renovated and is now divided into three new “neighbourhoods” that make it easier for shoppers to navigate their way around the mall. Each of Square One’s new neighbourhoods are characterized by a defining logo, interior design and furniture elements that create a unique look and feel.

•CitySide: Represented by a red clock icon, has the look and feel of a modern city. The high skylights create a feeling of openness, and the use of contemporary, edgy finishes in storefronts, lighting treatments, featured rest areas, ceramic tile flooring and modern metal finishes add to the ambience. The enhanced seating areas are in a serpentine configuration to follow the natural flow of the design in the flooring.
•NorthSide: Representated by an orange compass, has a more traditional feel. The use of beautiful, natural materials in the flooring including a decorative compass embedded in the floor design in one of the court areas. Also there are wood accents in the ceiling and leather upholstered furniture providing a different feel to the space as compared to the other two neighbourboods.
•CentreWalk: Represented by a purple tulip icon, is considered the Main Street in Square One and extends from one end of the mall to the other. The first of the neighbourhoods to be introduced, it has been updated with marble flooring, curvaceous wood furniture and new lighting creating a unique, bright and airy ambience.