On 1 July 2002, BAL Bashkirian Airlines Flight 2937 collides with DHL International Aviation ME Flight 611 in German airspace near Überlingen, killing all 71 people on board the two aircraft. The crew of Flight 611 followed the on-board traffic collision avoidance system (TCAS) instructions to initiate a descent. However, the crew of Flight 2937 followed the instructions of the air traffic controller instead of their TCAS and initiated a descent as well.

• Collision Catastrophe