While the Germans occupied the Netherlands during the World War II on May 10th 1940, Allied air forces carried out a number of operations over Rotterdam and the surrounding region, with 650 civilian victims and half the city destroyed These included bombing strategic installations, leaflet dropping, and during the last week of the war, the dropping of emergency food supplies.
In one incident, during a raid on the shipyards and dock area, the United States Army Air Forces accidentally bombed a residential area, killing hundreds. Until the 1990s, the raid that took place on 31 March 1943 was not mentioned in local school history lessons about the region’s war time experiences. In the run-up to the 50th anniversary of the raid, newspaper articles and a television documentary by Mr. van der Wel broke the taboo and the raid is now acknowledged with a memorial in a local park to the “Forgotten Bombardment”
Allied air forces (primarily the Royal Air Force and the United States Army Air Forces) carried out scores of raids on Rotterdam and the surrounding area, a 19 in total. About half the raids were within the city limits, the others were clustered around Nieuwe Waterweg, Schiedam (shipyards) and Pernis (petrochemical industries and fuel storage tanks). During the 128 raids casualties amounted to 884 killed and a further 631 wounded.
An attack on the city of Rotterdam on 31 March 1943, was made by 102 USAAF bombers. Their target was the shipyards and dock area, in the west of Rotterdam. The bombing took place at 12:25 (BST) in cloudy conditions and only 33 B-17’s dropped 99 tons of bombs.  The industrial area between Keilehaven and Merwehaven was hit. “A combination of strong wind and overcast conditions also caused great damage to the nearby residential areas, especially in the Bospolder-Tussendijken District”. The death toll was between 326 and 401[a] and made between 10,000 and 20,000 people homeless. This bombardment became known as the “Forgotten Bombardment” More then 2000 civilians were killed.in all these raids