In April 1943 "Graf Zeppelin" was again towed eastward, first to Gotenhafen, then to the roadstead at Swinemünde and finally berthed at a back-water wharf in the Parnitz River, two miles (3 km) from Stettin, where she had been briefly docked in 1941. There she languished for the next two years with only a 40-man custodial crew in attendance. When Red Army forces neared the city in April 1945, the ship's Kingston valves were opened, flooding her lower spaces and settling her firmly into the mud in shallow water. A ten-man engineering squad then rigged the vessel's interior with demolition and depth charges in order to hole the hull and destroy vital machinery. At 6pm on 25 April 1945, just as the Soviets entered Stettin, commander Wolfgang Kähler radioed the squad to detonate the explosives. Smoke billowing from the carrier's funnel confirmed the charges had gone off, rendering the ship useless to her new owners for many months to come.