The Telegraph Operator Who Held His Post in Halifax

Just before 9 a.m. on December 6, 1917, the Norwegian relief ship Imo clipped the bow of the French freighter Mont-Blanc in the Narrows of Halifax Harbour, at the diplomatic speed of about one knot. The collision spilled benzol on Mont-Blanc's deck. A spark from the steel hulls lit it. The crew, knowing what was in the hold, abandoned ship and rowed for the Dartmouth shore.

What the crew did not tell anyone, but what Patrick Vince Coleman gradually figured out, was that Mont-Blanc was carrying 2,925 metric tons of high explosive: 250 tons of TNT, 2,367 tons of picric acid, 62 tons of guncotton, and 246 tons of benzol on top of all of it. The cargo was bound for French munitions factories. The burning ship had drifted up against Pier 6, less than 200 metres from Coleman's railway dispatch office.

Coleman ran. Then he stopped, turned around, and went back. A passenger train from Saint John was due in within minutes. He sat down at his key and tapped: "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."

At 9:04:35 the ship detonated with a force later estimated at 2.9 kilotons of TNT — the largest human-made explosion until Hiroshima twenty-eight years later. The blast wave flattened a square mile of the city, threw a 1,140-pound anchor shaft 3.8 km inland, and pushed an 18-metre tsunami up the Dartmouth shore. About 1,950 people died. Hundreds more were blinded by flying window glass; ophthalmologists in the relief hospitals performed 249 enucleations in the days that followed.

The train Coleman warned stopped outside the city. Three hundred passengers lived. Coleman did not.