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
This weekend you can do take a look inside some of London's most iconic buildings.
The family of a father-of-three from East Ham have made a fresh appeal to catch his killer 20 years after he was murdered.
The Metropolitan Police has paid £45,000 in damages in an out-of-court settlement following the 'unlawful arrest' of a black motorist.