sentences:  Since then there has been opened other plants at Herøya, including a production plant for PVC (in 1951).Following the occupation of Norway by Nazi Germany in April 1940 the German occupying force had plans to build aluminium and magnesium plants in Herøya.The construction of the plant by Norsk Hydro in partnership with the Luftwaffe-operated "Nordische Aluminium Aktiengesellschaft" (Nordag) was however ended on 24 July 1943, when a bombardment by American B-17 Flying Fortresses completely destroyed the facilities as well as hitting parts of the surrounding areas, killing 55 people, including civilians.