On Fri, 14 Nov 2008 15:38:09 -0000, Andrew Heenan wrote:

I was at Euston bus station when a bus came round (people inside and
outside looking bemused) making an external announcement that "this
bus is under attack". I think this was before ibus though.
That was a pre-ibus thing. I've heard it a couple of times.

This example is from outside London:
http://uk.youtube.com/watch?v=iDGHuNfQZjA

I think the London version sounds less panicky.

Why doesn't it just send an automatic radio message to control telling
them to call 999, rather than relying on passers-by?