Bulgaria–United States relations to work. Bulgaria became a member of the Warsaw Pact on May 14, 1955. Though no Soviet troops were stationed on Bulgarian soil, in 1968, Zhivkov sent a Bulgarian division to join Polish, Hungarian and Soviet troops to crush a popular uprising in Prague. In 1978, the Bulgarian secret police were implicated in the assassination in London of Georgi Markov, a Bulgarian dissident who was a correspondent for the BBC World Service, Deutsche Welle radio and the U.S. sponsored Radio Free Europe. Markov was assassinated with a poisoned umbrella on September 7, Zhivkov's birthday. The rise of democratic movements across
London Waterloo station Aldershot, which was designed equally for the anticipated increase in military traffic in the area as well as commuters. Waterloo was bombed several times during World War II. On 7 September 1940, the John Street viaduct immediately outside the station was destroyed by a bomb, which prevented any services running for 12 days. Full services did not resume until 1 October, which particularly affected mail traffic with over 5,000 unsorted bags piling up on the station platform. Waterloo was closed again after bombing on 29 December 1940. It re-opened on 5 January 1941, on the same day that station offices