By 1944, by which time Norway was occupied by Germany as part of the Second World War, overhead wire had been installed on the Flåm Line. The locomotives at Thune and nearly completed, except for the transformers, which were at Per Kure. This was during the height of resistance sabotage, and workers at Per Kure had joined the communist resistance group Osvald. Because of the Allied bombing of Germany, Per Kure was thought to become part of a decentralized production chain and would be set to assemble aircraft engines. Osvald considered the plant a legitimate target and on 30 May 1944, the factory was blown up and the transformers severely damaged. Reconstruction of them took considerable time, in part because of the general lack of materials, and in part because the head engineer for the project disappeared during late 1944. In 1945, all three locomotives were sent to Myrdal Station for storage until the transformers were finished.