Fifteen years ago, over 50 million people across North America lost power.

Many Ontarians were in the dark for days.

People crowded stores for supplies and candles lit homes.

Though power companies believe it is unlikely that another outage that magnitude could happen again, it is still important to be prepared for an emergency.

A first aid kit, non-perishable food items, bottled water and non-electric lighting sources should be kept on hand.

In the event of a power outage, it is also recommended that you unplug appliances to avoid damage.

“There could be a surge, so you could actually damage your appliances once the power comes back on,” said Dean Murray with Reliance Home Comfort.

The 2003 blackout was caused by a sagging transmission wire in Ohio, which tripped a series of circuit breakers across the continent.