Ladies and gentleman, upon departing the train, may I remind you to take your rubbish with you. Despite the fact that you are in something that is metal, fairly round, filthy and smells, this is a tube train for public transport and not a bin on wheels.
As you're getting on the train, please let me point out that some of you stand too close to the edge of the platform. A 28-tonne train versus your body — I know which of the two my money would be on.
Would the guy with the piano accordion please put your trousers back on.