The Halifax Explosion (opens in new tab)

On 6 December 1917, in the harbour of Halifax, in Nova Scotia, Canada, two ships collided. One of them was a munitions ship loaded with explosives bound for the battlefields of the First World War. The result was one of the largest human-made explosions prior to the detonation of the first atomic bombs in 1945. Nearly 2,000 people died, another 9,000 were maimed, and more than 25,000 were left without shelter.