i) births and deaths 23rd September 1949: birth of Floella Benjamin (now Baroness Benjamin of Beckenham) who played the recurring character Professor Rivers in the first three seasons of the Sarah Jane Adventures . ii) broadcast anniversaries 23rd September 1967: broadcast of fourth episode of Tomb of the Cybermen . The Cybermen kill Kaftan; Toberman helps the others to freeze the Cybermen again, at the cost of his own life. 23rd September 1978: broadcast of fourth episode of The Ribos Operation . The Doctor is rescued by the shrivenzale, blows up the Graff, and converts the jethrik into the first segment of the Key to Time.