Many women were amongst the first operators of the world's first electronic computer, Colossus, at Bletchley Park, Buckinghamshire, England. Margaret O'Connell and Lorna Cockayne were members of WRN C Watch, but because of the top secrecy surrounding Colossus were not allowed to speak of their experiences until the 1970s. They did not continue in computing careers after the war. In February 2014, on the 70th anniversary of Colossus attacking its first Lorenz message, they returned to Bletchley Park, Block H to see a re-enactment of Colossus being used in codebreaking.