Ricin immunogenic in mice, rabbits, and humans. It has completed two successful clinical trials. Ricin has been involved in a number of incidents. In 1978, the Bulgarian dissident Georgi Markov was assassinated by Bulgarian secret police who surreptitiously shot him on a London street with a modified umbrella using compressed gas to fire a tiny pellet contaminated with ricin into his leg. He died in a hospital a few days later and his body was passed to a special poison branch of the British Ministry of Defence (MOD) that discovered the pellet during an autopsy. The prime suspects were the Bulgarian
1978 Balkan Bulgarian Tupolev Tu-134 crash or if the aircraft was under control at the moment of impact. 1978 Balkan Bulgarian Tupolev Tu-134 crash The 1978 Balkan Bulgarian Tupolev Tu-134 crash was an accident that occurred on 16 March 1978, when a Balkan Bulgarian Airlines Tupolev Tu-134 airliner on an international flight from Sofia, Bulgaria, to Warsaw Airport, Poland crashed. On departure from Sofia, the aircraft was climbing to , but at it turned on a heading of 050. It turned again to 270 then began an abnormal descent. The aircraft crashed near the village of Gabare, 130 km northeast of Sofia. All 73 on board