Halifax Explosion (Plain-Language Summary)

The Halifax Explosion happened on 6 December 1917. Two ships ran into each other. One of the ships was carrying munitions (war supplies), including explosives. The munitions were being sent to Europe to use in the First World War. The explosion destroyed the north end of Halifax. About 2,000 people died and 9,000 were wounded. About 25,000 lost their homes. The Halifax explosion was the biggest human-made explosion until August 1945. That was when the United States dropped two atomic bombs on Japan.

(This article is a plain-language summary of the Halifax Explosion. If you are interested in reading about this topic in more depth, please see the full-length entry, Halifax Explosion.)

Halifax Explosion

Halifax at War

Halifax was a very important port during the First World War. It was the main base of the Royal Canadian Navy. It was also a base for the Royal Navy (Britain’s navy). Tens of thousands of Canadian, American and British Empire troops passed through Halifax. They got on ships bound for Europe or got off ships returning from the war. But Halifax was not only full of soldiers and sailors. It was also full of weapons, wood, coal, and food headed for Europe.

What Happened?

The ships that ran into each other were the Imo and Mont-Blanc. The Imo was from Norway. It was going to New York to get supplies for the Belgian people and was leaving Halifax harbour. The Mont-Blanc was a French munitions ship. It was carrying a lot of explosives and was heading into the harbour.

The ships collided in the Narrows. This was the tightest part of the channel. All ships leaving the harbour were supposed to use the western (Halifax) side of the channel. All ships entering were supposed to use the eastern (Dartmouth) side. The Imo was supposed to use the western side of the channel. But it had to move to the eastern side to avoid two other ships. The Mont-Blanc was heading into the harbour, so it was travelling in the eastern section side of the channel too.

The officers and pilots of both ships tried to avoid each other. But the ships collided, and the Mont-Blanc ended up with a hole in its side. The collision also caused sparks that created a fire on the Mont-Blanc. The fire burned for almost 20 minutes. Large clouds of smoke rose from the ship. Unfortunately, this attracted many spectators on the shore.

Only a few people understood the danger. The crew of the Mont-Blanc quickly left the ship. Some harbour and navy officials also knew it might explode. At the railway yards, William Lovett, a chief clerk, found out that the Mont-Blanc was filled with explosives. He then told Coleman, a railway dispatcher. Coleman tried to warn trains coming to Halifax via telegraph so they would stop. Both Lovett and Coleman died in the explosion.


The Mont-Blanc exploded soon after 9:00 a.m. The explosion instantly killed about 1,600 people and destroyed or damaged thousands of buildings. It also caused a tsunami. About 400 people later died of injuries. Thousands more were injured; this included hundreds who were completely or partially blinded.


People rushed from other parts of Halifax to help. They included many soldiers and sailors. Soon after, relief workers and supplies arrived from across Nova Scotia. They also came from the rest of Canada and New England. Many people and countries donated money to help the injured and the homeless.


An inquiry was set up to find out why the explosion happened. In February 1918, the inquiry judge blamed the pilot and captain of the Mont-Blanc and the naval officer in command of the harbour. They were charged with manslaughter. But the charges were dropped because there wasn’t enough evidence. The case then went to the Supreme Court of Canada. It laid the blame equally on the Imo and Mont-Blanc. No one ever went to jail for causing the explosion.