The Texas City disaster killed nearly 600 in a ship explosion

On the morning of April 16, 1947, a fire broke out in the hold of the SS Grandcamp, a French-flagged freighter docked at the port of Texas City, Texas. Crewmen sealed the hatches and pumped in steam, hoping to smother the flames. Instead they pressure-cooked the cargo: roughly 2,300 tons of ammonium nitrate fertilizer, the same compound that fuels mining explosives.

At 9:12 a.m. the ship detonated. The blast was felt 150 miles away, flattened much of the waterfront, and wiped out nearly the entire volunteer fire department that had rushed to the dock. Burning debris ignited a neighboring vessel, the High Flyer, which was also loaded with ammonium nitrate; it exploded some 15 hours later.

At least 581 people died and more than 3,500 were injured — dozens of the dead were never identified.

The catastrophe reshaped American chemical-handling law and remains the deadliest industrial accident the country has ever recorded.