Trade unions in Northern Ireland have paid tribute after the sudden death of firebrand rail union leader Bob Crow.
The 52-year-old, who was the general secretary of the Rail, Maritime and Transport union (RMT), is believed to have suffered a heart attack at his home in east London.
The RMT union is affiliated to the Irish Congress of Trade Unions (ICTU).
Mr Crow was in Northern Ireland numerous times including May Day 2010 where he delivered a speech to trade unionists and took part in a march in Belfast.
He came to Northern Ireland for the trade union conference held every two years and was due to attend next month's event.
The general secretary of the ICTU, David Begg, led tributes to the union leader, who he described as "tireless in defence of his members' interests".
"Bob was a deeply committed and principled trade unionist who was tireless in defence of his members' interests and was a passionate advocate for working people everywhere," he said.
"A regular visitor to Ireland with members on these shores, Bob was well-known and highly regarded here.
"We are the lesser for his passing."
He added: "On behalf of the Irish trade union movement, I would like to extend deepest condolences and sympathies to all who were close to him and to the membership of the RMT." General secretary of Unite the Union Len McCluskey described him as a "highly successful fighter" for members' interests.
"Bob was a life-long and highly successful fighter for the interests of his members and for working people as a whole," he said. "I am sure that is the only epitaph he would have wanted."
Alison Millar, the deputy general secretary of NIPSA, said she echoed the sentiments contained in the Irish Congress's statement.
She added: "Bob will be a great loss to the movement."
The Communist Party of Ireland (CPI) offered its sympathies to Bob Crow's family, calling him a "great friend of Irish workers".
General secretary of CPI Eugene McCartan said: "Bob was one of the most outstanding trade union and working class leaders of this generation."