On the morning of November 20, 2009, Corporal Winston Matheson was traveling along Highway 107 in Dartmouth with two driver trainees on a Canadian Armed Forces bus. Corporal Matheson was observing one of the two driver trainees when an oncoming SUV crossed over into their lane and hit the bus head on.

Corporal Matheson, who stood to warn the driver about the oncoming vehicle, was thrown through the windshield at the time of impact.

After regaining consciousness, Corporal Matheson, who had suffered severe injuries, crawled back into the burning bus to rescue Corporal Steve Keddy. Corporal Keddy was knocked unconscious during the crash and was unable to escape the bus with the driver.