12 April 1989: death of Gerald Flood, who played Kamelion in 1983 and 1984, and also King John in The King's Demons (1983)
ii) broadcast anniversaries
12 April 1969: broadcast of sixth episode of The Space Pirates. Caven is defeated and captured; the Space Pirates are neutralised.
12 April 1975: broadcast of sixth episode of Genesis of the Daleks. The Daleks take over the bunker, killing everyone including (apparently) Davros; but the Thals bury them for centuries.
12 April 2003: webcast of "No Child of Earth, part 3", tenth episode of Death Comes to Time.