A Boeing 737 crashed in the Russian city of Kazan on Sunday killing all 50 on board, the aviation authority said, according to dpa. The Boeing of local carrier Tatarstan broke apart at Kazan airport, news agencies reported. All 50 people on board were killed, the Federal Air Transport Agency said, Interfax reported. However, the Emergency Situations Ministry said later that 52 people on board were killed - 46 passengers and 6 crew members. Early reports citing aviation officials blamed pilot error as the reason. They said that the plane, which had originated in Moscow, crashed after an aborted attempt to land.