Mick Cash, the RMT's senior assistant general secretary, said Mr Crow's death had rocked the trade union movement, both in this country and around the world.
The thousands of messages of condolence from every part of the globe are a testament to the courage, leadership and strength that Bob shared with so many people.
Whilst Bob Crow's funeral itself will be a strictly private affair, his friends and family recognise that many people will want to show their solidarity, respect and support, both on the day itself and on May Day. These arrangements give everyone a chance to play their part.
More top news
Combined strike action looks set to bring parts of the Tube and rail network to a halt this week.
Kenny Sansom has been left penniless and feeling worthless after decades of alcoholism.
A close associate of hate preacher Anjem Choudary has been jailed for knocking a boy unconscious because he was cuddling his girlfriend.