One almighty bang – the biggest man-made explosion before the development of nuclear weapons – caused death and destruction in a Canadian seaport 100 years ago today.
The Great Halifax Explosion demolished almost everything within a 2.5-mile radius. Its shockwave was felt 125 miles away and it killed at least 2,000 people, resulting in devastation on a previously unknown scale.
The explosion was centred on the harbour in Halifax, the capital of the Canadian province of Nova Scotia. It served as a gathering point for shipping convoys during the First World War. After assembling there, the escorted convoys would make the dangerous journey across the Atlantic to Europe, carrying vital war supplies, but all the time vulnerable to deadly German U-boat submarines.
On the foggy morning of December 6th, 1917, ships were gathering for just such a convoy when two of them, a French freighter and a Norwegian steamer, collided in the Narrows outside Halifax Harbour. The French ship, SS Mont-Blanc, was fully loaded with the high explosive TNT, plus highly flammable benzole fuel, guncotton and explosive picric acid. The Norwegian steamer, SS Imo, was empty apart from her own stores of coal for fuel. She was due to pick up relief supplies destined for Belgium when she docked later in New York.
When the two ships collided it started a fire aboard the French cargo ship when barrels of benzole toppled over and spilled, the fuel running into the hold and ignited by sparks. It effectively lit a fuse on a massive bomb. Seeing the danger, the crews of both ships fled their vessels, as did the crew of a British ship moored in the harbour and also filled with ammunition.
Only the crew of HMS Highflyer, the Royal Navy cruiser designated to escort the convoy, made any effort to avert the impending disaster. Its captain sent 23 men in a launch out to the SS Mont-Blanc with orders to sink her to put out the growing fire. Just as their launch drew alongside at 9-04am, the French ship erupted in a massive explosion.
The shockwave from the blast obliterated virtually everything within a half-mile radius, with significant damage caused to structures a further two miles away. The communities of Halifax and neighbouring Dartmouth, across the harbour, were devastated as white hot metal and burning debris rained down on them. Mont-Blanc’s forward gun was catapulted skyward with such force that landed three-and-a-half miles north of the explosion site, its 90mm barrel melted away.
More than 1,600 people were killed instantly, with hundreds more dying later from their wounds. At least 9,000 were injured and some estimates put the total death toll as high as 4,000. Many had been watching the fire aboard the Mont-Blanc from their homes when the explosion shattered and blew in the windows they were looking through. Almost 6,000 eye injuries were reported and more than 40 people permanently blinded.
Halifax’s main railway station collapsed, crushing scores of people inside. Fewer than 10 of the 500 pupils in the city’s school’s survived and at least 100 were killed in a sugar plant close to the harbour. More than 12,000 buildings were destroyed or badly damaged, including entire city blocks, and at least 25,000 people were left homeless.
The explosion also created a huge wave of water – a man-made tsunami – which lifted ships clean out of the harbour and wiped out the community of Mi’kmaq indigenous people who had lived in the nearby Tufts Cove area for generations.
Rescue efforts began almost immediately, with survivors attempting to locate injured people in demolished buildings and pull them free of the debris. Later, more rescue parties began to arrive by sea, rail and on foot. Their efforts were hampered by a growing snowstorm, but the heavy snowfall also helped by extinguishing the many fires started by the explosion.
It would be many months before the last bodies were found and buried, and several years before reconstruction of the devastated communities was complete.