The Lucky Donut

An announcement I heard on the Tube yesterday:

"There are currently severe delays on the Central line, due to a man under a train at Bethnall Green."

They wisely changed the description of the problem to a "severe customer incident" later on, which answered the question of whether or not the man was actually meant to be there (hey, he could have been fixing the brakes or something...) but I still need more information.  I just can't find any though!