General secretary of the Rail Maritime and Transport union Bob Crow has died.
The 52-year-old is believed to have suffered a heart attack and died in the early hours of Tuesday morning.
London Mayor Boris Johnson, with whom he clashed over plans for the Tube, said: "I am shocked. Bob Crow was a fighter and a man of character."
Labour leader Ed Miliband said he was "a major figure in the Labour movement and was loved and deeply respected by his members".
Mr Crow was elected general secretary of the RMT in 2002 following the death of former leader Jimmy Knapp.
The BBC's political editor Nick Robinson said Mr Crow "was, some argue, the most successful union leader in terms of securing jobs and pay for his members".
He is understood to have been due at a TUC executive awayday in Surrey on Monday, but was unable to attend because he was feeling unwell.
Very sad, shocking news. Thoughts and prayers with his family. I liked Bob Crow - he always struck me as a good old-school union leader. He seemed more focussed than any other contemporary union leader on his own turf, so to speak, of defending the interests of RMT members, and he was usually straight-talking yet also articulate when doing so. Moreover, it seems that he was successful, as well. The whole continuing to live in a council house when he was earning £145k a year wasn't brilliant, but there we go.
Anyway, NSGers - particularly Londoners, I suppose, since you'll have dealt with the effects of his work more than anyone else - thoughts on the man, his work, and his legacy?
