Previously posted at: https://www.history.com/this-day-in-history/texas-city-explodes
At 9:12 a.m. in Texas City’s port on Galveston Bay, a fire aboard the French freighter Grandcamp ignites ammonium nitrate and other explosive materials in the ship’s hold, causing a massive blast that destroys much of the city and takes nearly 600 lives.
The port of Texas City, a small industrial city with a population of about 18,000, was teaming with chemical plants and oil refineries that provided steady, good-paying jobs for much of the town. In the industrial sector, minor accidents and chemical fires were rather commonplace, and many stood around the port casually watching the reddish orange blaze that broke out on the Grandcamp early on a Wednesday morning. Twenty-seven members of the Texas City Volunteer Fire Department were called out to douse the flames, but the ship was so hot that the water from their fire hoses was instantly vaporized.
At 12 minutes past nine, the fire caught the freighter’s stores of ammonium nitrate, a compound used to make dynamite, and Texas City exploded. Wood-frame houses in the city were flattened, additional blasts were triggered at nearby chemical plants, and fires broke out across the city. The mushroom cloud from the blast rose 2,000 feet, and fragments of the Grandcamp were hurled thousands of feet into the air, landing on buildings and people. The ship’s anchor, weighing 1.5 tons, was flung two miles and embedded 10 feet into the ground at the Pan American refinery. The explosion was heard as far as 150 miles away.
Devastating fires burned for days, and on April 17 the freighter High Flyer, also loaded with nitrates, exploded, further devastating the port and causing a new string of explosions at nearby plants. Fortunately, most of Texas City’s population had been evacuated by then, and the city’s losses were primarily material. By late in the day on April 18, emergency crews had the situation under control. Some eyewitnesses said the scene was worse than anything they had seen in Europe during World War II. The Grandcamp explosion was the most devastating industrial accident in U.S. history, with 600 people killed and more than 3,000 wounded.