Huge blast shattered windows 100 km away
At about eight o’clock on the bright, clear morning of Dec. 6, 1917, the Norwegian ship SS Imo left its mooring in Bedford Basin, at Halifax, heading for the open sea and, eventually, New York.
At the same time, the French ship SS Mont-Blanc, carrying 2,300 tons of wet and dry picric acid, 200 tons of TNT, 10 tons of gun cotton and 35 tons of highly explosive benzol, headed into the harbour to await the convoy that would escort her to Europe and the First World War.
The two ships collided, setting off a fire aboard the Mont-Blanc, whose crew immediately took to the lifeboats, crying out warnings as they rowed furiously toward Dartmouth. Their ship, meanwhile, drifting toward Halifax, brushed along Pier 6 and set it on fire.
Numerous onlookers came down to the harbour to watch. Many more looked on from the windows of their workplaces and homes.
At 9:04 a.m., about 20 minutes after the collision, the Mont-Blanc exploded.
An estimated 1,650 people died instantly, but the death toll eventually climbed to more than 2,000. Nine thousand were injured and 6,000 were left homeless in what was the largest man-made explosion until the nuclear age. One thousand people suffered eye injuries from shattering windows and other flying debris. More than 1,600 buildings and seven ships were destroyed. Twelve thousand buildings were damaged.
Almost all of the north end of Halifax was destroyed. Much of what wasn’t immediately levelled burned to the ground as buildings, many loaded with coal for the winter, were razed.
The Mont-Blanc was torn into pieces. The barrel of one of her cannons landed five kilometres away. Part of her anchor went three kilometres in the opposite direction. Windows shattered in Truro, 100 kilometres away, and the shock wave was felt in Sydney, 400 kilometres away. The explosion was heard in P.E.I.
Relief efforts were hampered by a blizzard that dropped 40 centimetres of snow the following day. Within two months, 1,500 victims had been buried, some unidentified. Others were discovered only the following spring.
The explosion marked the first time that the Canadian Red Cross and the Salvation Army of Canada were involved in disaster relief. It also helped spark the formation of the CNIB.