December 6, 1917 dawned clear and sunny in Halifax. Before darkness fell, more than a thousand people would die, with another thousand to follow. Nine thousand more would be injured and maimed in the biggest human-made explosion the world had ever seen.

Halifax was booming. It was a military town in 1917 and World War 1 had been going on for 3 years. Halifax has one natural asset – one of the world’s natural harbours. It is one of the world's best, deepest and largest natural harbours. Its main harbour is relatively easy to protect from intruders. It has plenty of room for docks and ships. It had never been so busy because ships were carrying troops, supplies and munitions.

By 1917, three years of war in Europe had made Halifax a boom town. With a population of about 50,000, it was the largest in Atlantic Canada.

Since the start of World War I, Halifax Harbour had been busier than at any other time in its history…but harbour traffic control had failed to keep up. The Dartmouth ferries, civilian and military shipping, and small fishing and pleasure craft all moved about in the harbour. Collisions were frequent.

The main rules were the "rules of the road," which are much the same on the water as they are on land. Keep to the right, or starboard in traffic Signal your intentions and respect those of others

Where did people live? In 1917 in Halifax, people could tell a lot about you by where you lived on the Halifax peninsula. Many upper-class business and professional families lived in the “south end.” Dalhousie University was in the south end, along with most of the city's hospitals. The north end was more of a mix of communities-- black, white and native, immigrant, middle-class, working-class, Protestant and Catholic.

The twentieth century had brought miracles of modern communication. The telegraph was part of daily life. A message that moved around the world, door to door in mere hours, was still an amazing accomplishment in Telephones were catching on. They weren't considered basic appliances. Many businesses had them, but they were still the exception in most homes.

THE MONT BLANC The freight manifest for Mont-Blanc is a recipe for a giant bomb. Explosives Quantity Value in 1917 US$ TNT 226,797 kg $240,750 Wet picric acid 1,602,519 kg $2,230,999 Dry picric acid 544,311 kg $960,000 Guncotton 56,301 kg $65,165 Benzol 223,188 kg $104,376 Totals 2653,115 kg $3,601,290

On the night of December 1, Mont-Blanc slipped out of New York harbour by night and headed to Halifax to join a convoy. It flew no flags warning of its cargo: ship laden with explosives would be a prime target for German attack. A Halifax pilot boarded the ship outside the harbour around 4:00 pm on Wednesday, December 5. Francis Mackey was an experienced harbour pilot. But it was too late to enter: the anti-submarine nets had been closed for the night. Mont-Blanc's captain had to stay at sea for one more night.

IMO Inside the nets, in Bedford Basin, the Belgian relief ship Imo waited to head out in the morning. Coal for its boilers had arrived too late for it to leave that day. Now, Captain From was behind schedule.

Imo had no cargo on board. It was heading to New York to collect emergency supplies for civilians in war-torn Belgium. It carried a large sign on its side: "BELGIAN RELIEF." The sign was supposed to discourage German submarines, or U-boats, from sinking it as a military target.

In the morning… The submarine nets were opened and the two ships went about their business. The Imo was heading out the harbour and the Mont Blanc was heading in.

Stubborn ships… Then, through the morning haze, Imo faced Mont-Blanc moving up the Narrows. Mont-Blanc blew its whistle once, to say it had the right of way and would maintain its course: Imo should move to the right. But Imo blew its whistle twice in reply-- translation: I am staying where I am. There was a flurry of whistles between the two ships. Then, almost at the last minute, Mont-Blanc turned hard to the left…and Imo reversed its engines--hard astern. If only one of these moves had been made, the two ships would have avoided a collision - barely.

Fire Will Draw a Crowd – those 20 minutes after the crash… In the heart of Richmond, 14-year-old Barbara Orr was home from school for the day. She saw the collision from the dining room window. James Pattison, 13, was supposed to be on his way to school with his brother, but nothing would keep him from getting a look at all the to-do on the waterfront. They were just two of the thousands of people--office, factory and dock workers, delivery boys and naval cadets, housewives and schoolchildren--drawn to windows and look-offs. Almost no one realized the danger...not even the fire department.

The Explosion At 9:04:35 Mont-Blanc exploded with a force stronger than any manmade explosion before it. The steel hull burst sky-high, falling in a blizzard of red-hot, twisted projectiles on Dartmouth and Halifax. Some pieces were tiny; others were huge. Part of the anchor hit the ground more than 4 kilometers away on the far side of Northwest Arm. A gun barrel landed in Dartmouth more than 5 kilometers from the harbour. The explosion was heard in Truro.

More damage and devastation More than 1500 people were killed outright; hundreds more would die in the hours and days to come. Nine thousand people, many of whom might have been safe if they hadn't come to watch the fire, were injured by the blast, falling buildings and flying shards of glass.

And it wasn't over yet. Within minutes the dazed survivors were awash in water. The blast provoked a tsunami that washed up as high as 18 meters above the harbour's high-water mark on the Halifax side. And then a snow storm hit – bringing more than 16 inches of snow that very same night.

Who Helped Halifax: Money poured in from places as far away as China and New Zealand. The Canadian Government The British Government Boston, USA – donated money and supplies. They were the first to get supplies to a completely devastated Halifax.