Trivia: Location filming of "The War Games" took place in East Sussex during April 1969. To depict the desolate landscape of "no-man's land" during 1917, the location shoot was done at the Brighton Corporation Refuse Tip at Sheepcote, near Brighton. The very same location had been used just a few months before, also to depict "no-man's land in 1917" by Richard Attenborough, for his film Oh What A Lovely War.
Trivia: In one or two of the location filming scenes, Zoe is seen in the background struggling to hold her trousers up. Her belt broke, but filming was so far behind that the director said to carry on.
Answer: It was never destroyed on-screen; it was intact at the end of the TV movie, and destroyed by the start of the 2005 series. It was destroyed in the novel "The Ancestor Cell," but in a completely different manner to what happened in the series.
DaveJB