On the morning of December 6, 1917, the Canadian port city of Halifax was devastated by a catastrophic detonation that altered wartime maritime history. The tragedy unfolded when the French cargo vessel SS Mont-Blanc, packed with over 2,500 tons of volatile explosives including picric acid, TNT, and guncotton, attempted to enter Halifax Harbour. Due to strict wartime secrecy regulations, hazardous cargo manifests were kept confidential, leaving local harbor pilots completely unaware of the lethal powder keg navigating the narrow passage.
At the same time, the Norwegian vessel SS Imo was speeding out of the harbor to make up for delays caused by clearance paperwork. Conflicting whistle maneuvers and spatial misjudgments in the crowded shipping lane led the two ships to collide. The impact ignited drums of high-octane benzol stored on the Mont-Blanc's deck, resulting in an uncontrollable fire.
Twenty minutes later, the ship exploded with the force of roughly 2. 9 kilotons of TNT. The blast flattened nearby districts, killed nearly 2,000 people, injured 9,000 others, and triggered a devastating harbor tsunami.