The 1943 Filipstad explosion was a fire in an ammunition store at Filipstad in Oslo on Sunday, 19 December 1943, during the occupation of Norway by Nazi Germany. The fire started during the unloading of ammunition from the transport ship . The estimated amount of exploded ammunition varies from 800 to 1,200 tons. A large number of shells and grenades were tossed into the air and spread over the city. There were around 40 Norwegian casualties and around 75 Germans were killed, and 400 wounded. About 400 buildings were severely damaged.