Complex sentence: As a result of the derailment, over 200,000 people were evacuated in what was then the largest peacetime evacuation in North America up until the New Orleans evacuation of 2005 and the last explosion in the Greater Toronto Area until the Sunrise Propane blast in 2008.
Split into simpler sentences: As a result of the derailment, over 200,000 people were evacuated in what was then the largest peacetime evacuation in North America up until the New Orleans evacuation of 2005. It was the last explosion in the Greater Toronto Area until the Sunrise Propane blast in 2008.