Late delivery of coal. A misunderstood whistle blast. A slow-motion collision at barely a walking pace. In December 1917, a cascade of mundane errors collided with the pressures of World War I to create what was then the largest human-made explosion in history, leveling a city of 60,000 people in Nova Scotia.

This episode traces how a floating bomb ended up next to a thriving wartime port, the heroism that unfolded in the final minutes, and the staggering legacies in medicine, urban planning, and social justice. It is a story of systemic fragility, shared blame, and how disaster reshapes the world that follows.

• Why relaxed wartime rules put the explosive-laden Mont Blanc inside the harbor instead of out at sea
• The high-stakes game of maritime chicken between the Mont Blanc and the speeding, empty Imo
• Railway dispa ...