The creation of a crime scene, in which the road (carriageway and
footway) is taped off, and no pedestrians or vehicles are allowed to
proceed, is becoming a common occurrence. Where I live, I commonly see
the main road towards London sealed off, and traffic being diverted.
I've no idea whether buses are allowed to follow diversions, but in this
instance, the usual diversion route involves a railway bridge impassable
for double decker buses, and it is usual to see all the buses lined up
in the main road.

The eternal problem that anyone waiting for a bus needs to solve is that
if the service is supposedly every X minutes and the peson has been
waiting X x 3 minutes, does it mean that a bus is going to come at any
moment or does it mean that a disaster or event has occurred and the bus
is not coming at all.

The headlines of the Evening Standard last night was "POLICE FAILED TO
STOP DEATH RAVE" and follows with a story about how a boy died from
drinking beer laced with ketamine after attending an illegal rave. The
police are under scrutiny for not attempting to stop the rave which
apparently started on Saturday night going on to early hours of Sunday
Morning. What the police did do was to tape out a crime scene at 08:15
on Sunday Morning outside East Croydon railway station which prevented
any trams or buses from moving. It didn't involve the railway service
but anyone disembarking from a train with the intention of continuing
journey by bus or tram would have been stuck.

The tram indicators were operating as normal, this destination x
minutes, that destination y minutes, and no indication that anything had
happened. I presume that must have been the same throughout the nework.