Doug Ross @ Journal

The Largest Man-Made Explosion Prior to Hiroshima

It was December 6, 1917, a bright, crystal clear day in Halifax, Nova Scotia. As a port city, Halifax was a bustling hive of activity. Troop ships, supply vessels and other vehicles were engaged in the commerce of World War I.

Near eight in the morning, the Belgian supply ship Imo   headed out of the harbor. At the same time, the French vessel Mont Blanc   nosed its way into the harbor, preparing to join up with a convoy to cross the Atlantic.

In the Mont Blanc's   hold, and even laid on its deck due to lack of space, were tons of ammunition and explosives: benzol, artillery ammo, gun cotton, pitric acid -- a building block of explosives -- and over 400,000 pounds of TNT.

A series of navigational and signalling errors resulted in the Imo   crossing directly in front of the Mont Blanc  . The former struck the latter, missing the TNT, but creating an immense gash in the stores of benzol on deck. The resulting sparks of the collision set the stage for catastrophe.

The crew of the Mont Blanc   understood instantly that they needed to evacuate. They abandoned ship using the lifeboats, and rowed full bore for Dartmouth while their ship burned. Their screamed warnings were either not heard or ignored.

The Mont Blanc   careened aimlessly past a pier and set it afire. The Halifax Fire Department answered the call and began connecting their equipment to the nearest hydrant when the flaming ship disappeared. A white flash -- the largest man-made explosion prior to the nuclear age -- turned the harbor into an inferno of biblical proportions.

More than 1,900 people were killed instantly and almost 10,000 were injured. 325 acres of land were destroyed and any remaining structures simply burned. The Mont Blanc   was pulverized: one if its cannons landed more than three miles away while a piece of its anchor, which weighed over 1,000 pounds, sailed two miles in the opposite direction. The shock wave was felt over 250 miles away and windows shattered as far as 50 miles from the explosion.

Unfortunately, about twenty minutes elapsed between the inital collision and the devastating explosion. This was enough time for many people, including school children, to rush to the harbor to view the spectacle of the burning vessel. The glass launched by the explosion caused eye injuries to about 1,000 people...

The Halifax explosion