On July 2, 1942, a German aircraft crashed at the eastern side of Hansakollen in Nordmarka, Oslo, on its way to Gardermoen. It was a rainy and foggy day, and the pilot did not see the steep hills. Three Germans on board were killed and the tree tops in the area were chopped off by the plane.
You can still find the remains of the Dornier DO17 aircraft, together with an information placard about the incident, around 2.4 km from Movatn train station. The remains are located in a nature preservation area, and although there are trails to the spot, there are few signs with information about it, so you need a map and the coordinates to get there.