Until recently, British Rail was probably the holder of the most stupid excuses for train cancellations or delays, with ones like these, which are now well-known throughout the UK:

leaves on the line

the wrong kind of snow

and more recently, a lesser known one about

a cow on the line

But today, on the travel news, a company has really excelled itself, The reason for delays?

a tree had fallen on the track

This doesnt really sound very remarkable, until you realise that the company in question is London Underground.