O'Hea was about 23 years old, and a private in the 1st Battalion, Rifle Brigade (Prince Consort's Own), British Army stationed in Canada when the following deed took place for which he was awarded the On 9 June 1866 at Danville, Quebec, Canada, a fire broke out in a railway car containing 2000 lb (900 kg) of ammunition, between Quebec and Montreal. The alarm was given and the car was disconnected at Danville Railway Station. While the sergeant in charge was considering what should be done, Private O'Hea took the keys from his hand, rushed to the car, opened it and called for water and a ladder.
It was due to this man's example that the fire was suppressed. Graham Fischer was present at the death but did not describe the specifics on the event. A recent book by Elizabeth Reid, The Singular Journey of O'Hea's Cross, poses the theory that Timothy O'Hea in fact died in Ireland, shortly after his discharge from the British Army in 1868.