A docked Norwegian ship on a hot summer day (T° > 27° C) held a total of 3,133 tonnes of 50 kg bagged ammonium nitrate grains in cargo holds #1, 3 and 5; in the deck cargo area above these holds, more than 2000 t of combustible or inflammable substances were being stored in drums, including: 350 t of fuel oil, paints, lubricants, rubber, polystyrene, paraffin, methyl ethyl ketone, and butyl alcohol. Around 12:30 pm, a white smoke turned yellow in exiting a venting tube from Hold 3. The vapour extinction system was needlessly activated as it introduced heat in the hold and given the presence of oxygen in the ammonium nitrate. Red smoke was seen in the exhaust from the hold’s other venting tubes. A low rumble could be heard. Emergency workers opened the vibrating access panel. The fire was growing in intensity, with explosions ejecting cargo onto the ship’s deck or in the water. Flames reached some warehouses along the dock (triggering a domino effect). A tugboat towed the crippled ship away from the port, though with its superstructures already ablaze, the vessel ran aground at 2 pm on a bank located too close to the city. At 5 pm, the fire was out of control, as drums of oil stored in Hold 2 ignited and flames began spewing from Hold 1, which was storing 739 tonnes of ammonium nitrate. The boat was now adrift; at 5:25 pm a big explosion, followed by an enormous plume of smoke, killed 26 people and hurt more than 500 downtown. A 5-m wave engulfed the docks, and the city endured a bombardment of material projectiles, causing major damage (the fire spread to a gas plant and oil depots, more than 4000 home destroyed). Glass panes were shattered up to 70 km from the blast, and ironwork was found as far as 22 km away. Paraffin and other molten materials had seeped into the ammonium nitrate stock, triggering its detonation.