Video: 'Hamburg’s Citizens Burnt Alive - War Against Humanity 071 - July 31, 1943' (July 27, 1943, at 15:35)

(Tuesday, July 27, 1943, shortly before midnight Central European Summer Time; during the Allied bombing of Hamburg during World War II, codenamed Operation Gomorrah, part of the European Theater of World War II) — In the greatest single-day loss of life in wartime, up to then, more than 30,000 residents of the German port city of Hamburg were killed tonight when British bombers carried out Operation Gomorrha.

Because of unusually dry conditions, the high combustibility of buildings in the working class neighborhoods of Billwärder-Ausschlag, Borgfelde and Hamm, and the use of more than 1,000 tons of incendiary bombs, a firestorm was created, bringing powerful winds to spread the destruction.

Video: 'Operation Gomorrah: The Allied Firebombing of Hamburg'

Most of the victims died from carbon monoxide poisoning inside basement shelters, and it took two days for the streets to cool down enough for rescue teams to look for survivors.

“At the heart of the apocalyptic fire”, author Frederick Taylor would write later, “there were no survivors found, none at all.”

An estimated 18,474 people died on this night. A large number of those killed were seeking safety in air raid shelters and cellars.

Video: 'The World At War: Whirlwind Bombing Germany' (Operation Gomorrah at 31:53)

The firestorm consumed the oxygen in the burning city above and the carbon monoxide poisoned those sheltering below.

The furious winds created by the firestorm had the power to sweep people up off the streets like dry leaves.

In all, an estimated 37,000 civilians were killed and another 180,000 were wounded by the Allied raids during Operation Gomorrah, which had begun July 24 and would continue through Aug. 3, 1943.