From February 1942 to March 1945, the Allied forces launched about 40 strategic bombing raids on Kassel in the central German state of Hesse during World War II. The bodies of the victims of the air raids on Kassel residents were placed in the square. It took weeks to accumulate all the dead bodies of Kassel citizens from the streets and abandoned cellars in the streets. The American army occupied Kassel on April 3, 1945. Kassel had a population of about 236,000 in 1939, of which only about 50,000 remained. At least 90 percent of the old city center was in ruins. The indiscriminate and intensive bombing in the name of demoralizing the German people was condemned after the war as a terrorist bombing. Extensive sweeps of bombed and un-bombed buildings devastated the city.
The worst attack was the British bombing raid of October 22-23, 1943, which destroyed most of Kassel's city center, but the city's industrial areas remained. The only victims of the targets were the citizens of Kassel. About 150,000 inhabitants were bombed and at least about 10,000 people were killed. The heaviest air raids caused fires that burned for about seven days. About 569 bombers dropped about 1,800 tons of bombs and 460,000 magnesium incendiary bombs on the old city of Kassel for about 80 minutes.
The pressure wave of the explosions tore off roofs, windows and doors. Many of the buildings, mostly wooden, were engulfed in flames within about 15 minutes by the bombs raining down from the sky. Kassel had narrow streets where the fire could easily spread. The highest temperature reached about 1,500 degrees Celsius, and the wind speed reached about 160 km/h. All the oxygen was sucked out of the air and the inhabitants who reached the first safety of the basement soon suffocated to death. Most of the residents fled to the basement of the building they were living in. Ventilation pumps sucked in flames and smoke from the outside world in the opposite direction. Many residents could not find their way out to the surface, leading to chaotic hellish conditions in the narrow rooms and hallways where they got lost.
