Halifax Explosion



A picture of the pyrocumulus cloud

Date: 6 December 1917
Time: 9:04:35 am (AST)
Location: Halifax, Nova Scotia, Canada
Deaths: 1,782 (confirmed)
Non-fatal injuries: 9,000 (approximate)

The Halifax Explosion was a disaster that occurred in Halifax, Nova Scotia, Canada, on the morning of 6 December 1917. SS Mont-Blanc, a French cargo ship laden with high explosives, collided with the Norwegian vessel SS Imo in the Narrows, a strait connecting the upper Halifax Harbour to Bedford Basin. A fire on board the Mont-Blanc led to a massive explosion that devastated the Richmond district of Halifax. Approximately 2,000 people were killed, largely in Halifax and Dartmouth, by the blast, debris, fires, or collapsed buildings, and an estimated 9,000 others were injured. The blast was the largest human-made explosion at the time, releasing the equivalent energy of roughly 2.9 kilotons of TNT (12 TJ).

Mont-Blanc was under orders from the French government to carry her cargo from New York City via Halifax to Bordeaux, France. At roughly 8:45 am, she collided at low speed, approximately one knot (1.2 mph or 1.9 km/h), with the unladen Imo, chartered by the Commission for Relief in Belgium to pick up a cargo of relief supplies in New York. On the Mont-Blanc, the impact damaged benzol barrels stored on deck, leaking vapours which were ignited by sparks from the collision, setting off a fire on board that quickly grew out of control. Approximately 20 minutes later at 9:04:35 am, the Mont-Blanc exploded.

Nearly all structures within an 800-metre (half-mile) radius, including the community of Richmond, were obliterated. A pressure wave snapped trees, bent iron rails, demolished buildings, grounded vessels (including Imo, which was washed ashore by the ensuing tsunami), and scattered fragments of Mont-Blanc for kilometres. Across the harbour, in Dartmouth, there was also widespread damage. A tsunami created by the blast wiped out the community of the Mi'kmaq First Nation who had lived in the Tufts Cove area for generations.

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Explosion

At 9:04:35 am the out-of-control fire on board Mont-Blanc set off her cargo of high explosives. The ship was completely blown apart and a powerful blast wave radiated away from the explosion initially at more than 1,000 metres (3,300 ft) per second. Temperatures of 5,000 °C (9,000 °F) and pressures of thousands of atmospheres accompanied the moment of detonation at the centre of the explosion. White-hot shards of iron fell down upon Halifax and Dartmouth. Mont-Blanc's forward 90-mm gun landed approximately 5.6 kilometres (3.5 mi) north of the explosion site near Albro Lake in Dartmouth with its barrel melted away, and the shank of Mont-Blanc's anchor, weighing half a ton, landed 3.2 kilometres (2.0 mi) south at Armdale.

A cloud of white smoke rose to at least 3,600 metres (11,800 ft).[58] The blast was felt as far away as Cape Breton (207 kilometres or 129 miles) and Prince Edward Island (180 kilometres or 110 miles). An area of over 160 hectares (400 acres) was completely destroyed by the explosion, and the harbour floor was momentarily exposed by the volume of water that was displaced. A tsunami was formed by water surging in to fill the void; it rose as high as 18 metres (60 ft) above the high-water mark on the Halifax side of the harbour. Imo was carried onto the shore at Dartmouth by the tsunami. The blast killed all but one on the whaler, everyone on the pinnace and 21 of the 26 men on Stella Maris; she ended up on the Dartmouth shore, severely damaged. The captain's son, First Mate Walter Brannen, who had been thrown into the hold by the blast, survived, as did four others. All but one of the Mont-Blanc crew members survived.

Over 1,600 people were killed instantly and 9,000 were injured, more than 300 of whom later died. Every building within a 2.6-kilometre (1.6 mi) radius, over 12,000 in total, was destroyed or badly damaged. Hundreds of people who had been watching the fire from their homes were blinded when the blast wave shattered the windows in front of them. Overturned stoves and lamps started fires throughout Halifax, particularly in the North End, where entire city blocks burned, trapping residents inside their houses. Firefighter Billy Wells, who was thrown away from the explosion and had his clothes torn from his body, described the devastation survivors faced: "The sight was awful, with people hanging out of windows dead. Some with their heads missing, and some thrown onto the overhead telegraph wires." He was the only member of the eight-man crew of the fire engine Patricia to survive.

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The death toll could have been worse had it not been for the self-sacrifice of an Intercolonial Railway dispatcher, Patrick Vincent (Vince) Coleman, operating at the railyard about 230 metres (750 ft) from Pier 6, where the explosion occurred. He and his co-worker, William Lovett, learned of the dangerous cargo aboard the burning Mont-Blanc from a sailor and began to flee. Coleman remembered that an incoming passenger train from Saint John, New Brunswick, was due to arrive at the railyard within minutes. He returned to his post alone and continued to send out urgent telegraph messages to stop the train. Several variations of the message have been reported, among them this from the Maritime Museum of the Atlantic: "Hold up the train. Ammunition ship afire in harbor making for Pier 6 and will explode. Guess this will be my last message. Good-bye boys." Coleman's message was responsible for bringing all incoming trains around Halifax to a halt. It was heard by other stations all along the Intercolonial Railway, helping railway officials to respond immediately. Passenger Train No. 10, the overnight train from Saint John, is believed to have heeded the warning and stopped a safe distance from the blast at Rockingham, saving the lives of about 300 railway passengers. Coleman was killed at his post.

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Legacy

See also: Halifax Explosion in popular culture

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In 1918, Halifax sent a Christmas tree to the City of Boston in thanks and remembrance for the help that the Boston Red Cross and the Massachusetts Public Safety Committee provided immediately after the disaster. That gift was revived in 1971 by the Lunenburg County Christmas Tree Producers Association, which began an annual donation of a large tree to promote Christmas tree exports as well as acknowledge Boston's support after the explosion. The gift was later taken over by the Nova Scotia Government to continue the goodwill gesture as well as to promote trade and tourism. The tree is Boston's official Christmas tree and is lit on Boston Common throughout the holiday season. In deference to its symbolic importance for both cities, the Nova Scotia Department of Natural Resources has specific guidelines for selecting the tree and has tasked an employee to oversee the selection.

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