What was the deadliest industrial accident in American history?

Texas City explosion of 1947 was an industrial disaster sparked by the fire and explosion of the SS Grandcamp on April 16–17, 1947 in Texas City, Texas. The blast set off a chain of fires as well as a 15-foot (4.5-metre) tidal wave. Between 400 and 600 people were killed, with as many as 4,000 injured.

On the morning of April 16, the French-owned Grandcamp was preparing to finish loading a consignment of ammonium nitrate fertilizer at the port of Texas City, near Galveston.

About 8:00 AM crew members noticed smoke in the cargo area, where 2,300 tons of the fertilizer had already been stowed. In order to keep the cargo intact, the crew decided not to use water to extinguish the fire; they instead tried sealing the hatches to snuff out the flames. Unknowingly, they had created a bomb.

Shortly after 9:00 AM a massive explosion that was heard as far as 150 miles (240 km) away occurred. The initial explosion wiped out the Texas City Fire Department. The resulting fire destroyed the dock area and engulfed the nearby Monsanto Chemical Company plant. A mushroom cloud rose 2,000 feet (600 metres) into the air, and two small planes passing above were destroyed.

A nearby ship, the SS High Flyer, which was carrying huge amounts of sulfur, also caught fire and exploded, and crude oil tankers near the site burned for days, consuming massive amounts of petroleum. The enormous wave triggered by the blast flattened numerous buildings, leaving as many as 2,000 people homeless.