M. J. Powell wrote:

There was (so SWMBO tells me) a Doctor Who story set in a disused tube
stn,

From recollection three stories, though none feature disused stations.

In "The Web of Fear" (1968) the TARDIS materialises in the tube and finds
the network shut down and London evacuated due to an invasion by robotic
Yeti. A number of tube stations are seen, but all scenes were recorded in
studio (though the sets were so convincing that London Underground
believed
otherwise!).

Was that the one where an actor died on the set and the others ad libbed
around his part? The sets were in the studio, but as a number of parallel
tunnels. It went out live.

I've never heard of an actor dying on set in Doctor Who (the only death in
production I've heard of was when an actor was cast in the 1980s but
murdered before recording).

Oh and it wasn't live but recorded virtually "as live" with very few breaks
due to videotape being difficult to edit.