On a cold December 6, in 1917, it seemed as though the doors of hell had burst asunder in Halifax, Nova Scotia. French munitions ship the SS Mont-Blanc collided with Norwegian supply ship the Imo at 8:40 in the morning. Twenty-five minutes later, the biggest single man-made explosion prior to the atomic bomb tests of 1945 laid waste to the harbor and everything around it.
The force of the blast was so great that all the buildings within a 16-mile radius were all but obliterated and iron railings were bent like soda straws. A tsunami was created after water filled the space where the harbor bottom was briefly exposed due to the amount of water that had been vaporized. In total, 2,000 people were killed, with a further 9,000 injured. The city was devastated, and parts of it were turned into a wasteland as a built-up area of 500 acres on the nearby shore was wiped off the map.
Due to traffic congestion in the Narrows, a section where ships passed between the basin and outer harbor, the Norwegian ship Imo was not in the lane it should have been. The Mont-Blanc was moving in the other direction and blew its whistle in warning, but the Imo signaled it would not or could not change course. Hearing the signals, sailors on other boats gathered to watch the impending collision. Last-minute evasive action by both ships – the Imo reversing its engines and the Mont-Blanc turning hard to the left – actually contributed to their colliding.
When the two ships struck each other, the world changed forever in Halifax.
The Imo’s effort to disengage caused sparks to fly in the Mont-Blanc’s hull, and the benzol drums that had been crushed on the deck of the fully-loaded munitions ship were ignited by highly unstable picric acid. Very soon, the fire that started was out of control and the explosion became inevitable.
When it came, the explosion was massive. When 130 major explosions were compared, the team behind a scientific study reported: “Halifax Harbour remains unchallenged in overall magnitude as long as five criteria are considered together: number of casualties, force of blast, radius of devastation, quantity of explosive material, and total value of property destroyed.”
To put things in perspective, the explosion had about the same force as three kilotons of TNT. The Mont-Blanc was utterly destroyed, with parts of the ship flying almost 1,000 feet into the air, while the Imo was swept away by the tsunami.
The human toll of the disaster was shocking: at least 1,500 were killed instantly by the blast, collapsing buildings, and the tsunami – which surged up to 60 feet over the harbor’s high-water mark. More deaths occurred later among those who had been injured by debris or who were caught in the infernos sparked in Halifax. Firefighter Billy Wells (the only survivor among the crew of the first motorized fire truck in Canada) said: “The sight was awful, with people hanging out of windows dead. Some with their heads missing, and some thrown onto the overhead telegraph wires.”
Yet amongst the devastation there were some miraculous survival stories as well. One example is that of ‘Ashpan Annie’, who was blown into the container of ashes beneath the stove in her house. The ashes were warm enough to protect her from the bitter cold until she was found over 24 hours later. Her mother and brother were killed by the force of the blast – which tore apart their house – but she lived to a ripe old age, dying in 2010.
The investigation into the cause of the explosion started shortly after the disaster. The captain and pilot of the Mont-Blanc as well as the naval officer overseeing harbor movements were all charged with manslaughter. However, the two men aboard the Mont-Blanc had their charges dropped, while the third man was acquitted. In 1919, the Supreme Court of Canada ruled that both the ships were equally to blame for the errors that resulted in the devastation of Halifax and her neighboring communities. Regardless of blame, the Halifax explosion remains one of the worst events of its kind in history.