The Nedelin catastrophe or Nedelin disaster, known in Russia as the Catastrophe at Baikonur Cosmodrome, was a launch-pad accident that occurred on 24 October 1960 at the Baikonur Cosmodrome in the Kazakh SSR, during preparations for the first test flight of a prototype R-16 intercontinental ballistic missile. The missile's second-stage engine ignited while it was still on the pad, rupturing the first stage and causing a fire and explosion among military and technical personnel gathered around the fuelled missile. The Soviet authorities suppressed information about the disaster for decades and falsely reported that Chief Marshal of Artillery Mitrofan Ivanovich Nedelin, head of the R-16 development programme, had died in an air crash. A 1994 state commission report gave the death toll as 78, including 74 killed at the site and four who later died in hospital; other estimates have varied. The accident is commonly described as the deadliest launch accident associated with rocket or spaceflight activity, although the R-16 was being tested as a military missile.