A single warning can change everything. Before the atomic bomb, the Halifax Explosion was the largest human-made blast in history. This Heritage Minute tells the story of Vince Coleman, a railway dispatcher whose final telegraph message in 1917 saved hundreds of lives. Interesting fact: His chilling last words were, "Guess this will be my last message. Good-bye, boys." | Historica Canada

Over the last 51 years, one photographer has captured more than 100,000 moments of Halifax Harbour history. www.cbc.ca/1.4191741 | CBC Nova Scotia