On 13 September 1997, a German Air Force Tupolev Tu-154M observation aircraft and a United States Air Force C-141B Starlifter transport aircraft were destroyed in a mid-air collision while cruising at 35,000 feet (11,000 m) off the coast of Namibia. All 33 people on board both aircraft were killed. At the time of the collision, the Tupolev was flying on a southerly route from Niamey, Niger, to Cape Town, South Africa, while the C-141 was heading northwest from Windhoek, Namibia, to Ascension Island.