Around 4:10 p.m. on the warm summer afternoon of Thursday, August 14, 2003, the power went out in Toronto.

It wasn’t a normal outage, Torontonians would soon find out. An estimated 10 million people in Ontario and 45 million people in eight U.S. states were without power. Toronto joined Cleveland, New York City, Baltimore, Buffalo, Detroit, Newark and others major cities to lose electricity.

The outage originated from a software bug in an Ohio energy management company. The chain of events started at about 12:15 p.m. that day and ended at 4:13 p.m.

Streetcars were abandoned around the city, restaurants and bars sold perishable food and drinks at discounts and all flights into and out of Toronto's Pearson International Airport were grounded.

SkyDome, now called the Rogers Centre, kept its retractable roof open to save power in the days following.

Power was restored by 3 a.m. on August 15, bringing to a close almost one full day in the dark for Toronto.

CBC charted the course of the blackout here.