On the morning of December 6, 1917, the bustling port city of Halifax, Nova Scotia, became the site of a devastating maritime tragedy. The SS Mont-Blanc, a French cargo ship packed to capacity with volatile explosives—including picric acid, TNT, gun-cotton, and benzol—was entering Halifax Harbour. At the same time, the SS Imo, a Norwegian vessel chartered to pick up relief supplies in New York, was departing the harbour through the Narrows at an unsafe speed.
Navigational confusion caused both captains to misinterpret each other's signals and maneuvers. Desperate maneuvers came too late, and the Imo struck the starboard bow of the Mont-Blanc. The collision ripped open barrels of high-octane fuel on the Mont-Blanc's deck, causing a sudden fire that spread instantly.
Knowing the extreme danger of his cargo, Captain Aimé Le Mêdec and his crew abandoned ship, but were unable to warn the people on shore. For roughly twenty minutes, the unmanned, burning Mont-Blanc drifted toward Pier 6 as thousands of onlookers gathered to watch the spectacular blaze. At 9:04 AM, the vessel exploded with a force equivalent to roughly 2.
9 kilotons of TNT. The blast instantly leveled two square kilometers of Halifax, generated a tsunami that swept over coastal communities, and sent a shockwave felt hundreds of miles away. Over 1,900 people died instantly, and thousands were injured or blinded by shattered glass.
The Halifax Explosion remains the most severe non-nuclear artificial detonation in human history.