Ricin the attack on Georgi Markov another Bulgarian defector, Vladimir Kostov, survived a similar attack. Kostov was standing on an escalator of the Paris metro when he felt a sting in his lower back above the belt of his trousers. He developed a fever, but recovered. After Markov's death the wound on Kostov's back was examined and a ricin-laced pellet identical to the one used against Markov was removed. Several terrorists and terrorist groups have experimented with ricin and caused several incidents of the poisons being mailed to U.S. politicians. For example, on May 29, 2013 two anonymous letters sent to
London Waterloo station Rail announced that platforms 20–24 would be fully refurbished in order to increase capacity at Waterloo by 30%. Communications manager Kevin Parker stressed that the international platforms were only designed to cope with six trains per hour, well below the expected capacity for commuter services. The platforms closed in September 2017 for the works, with a revised timetable to be published the following year. Waterloo station was to be the central London terminus for the proposed Heathrow Airtrack rail service. This project, promoted by British Airport Authority Limited (BAA), envisaged the construction of a spur, from on the Waterloo to