Author(s): Kathleen Robinson. Published on November 2, 2015.

Harbor Disaster

The 1917 Halifax explosion. BY KATHIE ROBINSON

ON THE MORNING OF DECEMBER 6, 1917, Dr. M.J. Burris felt his house shake. Burris lived on the eastern shore of Halifax Harbour in Nova Scotia, and at first he thought the rumble was a bomb; the world was at war, after all, and Halifax was the North American base for the British Royal Navy.

Minutes later, Burris heard another, louder explosion, and he hustled his family into the cellar for safety. That’s where they were when a third, enormous explosion occurred. The blast damaged their home and destroyed much of the surrounding area, reducing a thriving port to smoking rubble.

Burris’s story, part of the Halifax Explosion Archives, is just one facet of what occurred that morning when two ships—the French vessel SS Mont-Blanc and the Norwegian ship SS Imo—collided in the city’s harbor. The Imo, on its way to New York to pick up relief supplies for Belgium, and the Mont-Blanc, carrying munitions from New York to France to aid in the French war effort, met in the Narrows, a strait that connected Halifax Harbour and the Bedford Basin. The Imo was traveling faster than the 5-knot speed limit as she approached the Mont-Blanc. The pilot of the Mont-Blanc signaled the Imo to change course, but the Imo refused. At 8:45 a.m., the Imo struck the Mont-Blanc amidships.

The Mont-Blanc carried TNT, picric acid, high-octane fuel, and gun cotton. The collision caused the fuel barrels in the ship’s hold to break open, emitting vapors that soon ignited. Nineteen minutes after the collision, the Mont-Blanc’s cargo erupted in a massive explosion, releasing energy equivalent to 2.9 kilotons of TNT. In addition to a devastating shock wave, the explosion also produced a tidal wave that sent water 59 feet (18 meters) above the high-tide mark on the Halifax side of the harbor. According to the Canadian Broadcasting Corporation, everything inside a 1.2-mile (2-kilometer) radius of the explosion was destroyed; some communities were obliterated. More than 13,000 buildings—homes, factories, schools—were damaged or destroyed, as were rail lines, electric wires, and water piping. Fires broke out in the remains of wooden buildings until entire streets were ablaze.

The human toll was staggering. Doctors triaged the injured, whose numbers eventually rose to 9,000. A temporary morgue was set up to house the bodies of the estimated 2,000 people who died. Most were killed in building collapses and fires, although some of those trapped in the rubble died of exposure during the blizzard that began that night and lasted throughout the following day.

An inquiry found the Mont-Blanc to be at fault, but the finding was later thrown out by the Supreme Court of Canada and the British Privy Council, which blamed both ships for the disaster.

The Halifax blast was the largest man-made explosion until the development of nuclear weapons almost three decades later. Memorials were built to honor the dead, the largest of which is at Fort Needham, where the Halifax Explosion Memorial Bells are rung each year on December 6 to remember those who perished.

KATHLEEN ROBINSON is NFPA Journal editorial operations manager. Top Photograph: Nova Scotia Archives and Record Management