1965 Northeast Blackout

The 1965 Northeast Blackout was a massive power outage that affected parts of Ontario in Canada and Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont in the United States on November 9, 1965. It was the most significant power failure in North American history at the time, leaving approximately 30 million people without electricity for up to 13 hours.

The blackout was caused by a single relay failure at the Sir Adam Beck Hydroelectric Power Station in Ontario, which triggered a cascading failure that propagated through the interconnected power grid. The event demonstrated the vulnerability of tightly coupled infrastructure systems and became a catalyst for the development of modern grid reliability standards.