1979 Mississauga train derailment
The Mississauga train derailment, also known as the Mississauga Miracle, occurred on November 10, 1979, in Mississauga, Ontario, Canada, when a CP Rail freight train carrying hazardous chemicals derailed and caught fire. More than 200,000 people were evacuated in the largest peacetime evacuation in North America until Hurricane Katrina.
Source: Wikipedia — 1979 Mississauga train derailment (CC BY-SA 4.0)