The Script's guitarist Mark Sheehan missed out on part of the band's greatest hits tour before his death at 46.
The band, known for huge hits such as Hall of Fame, Man Who Can't Be Moved and Breakeven, announced that Mark had died today in hospital after a short illness.
Last year, Mark missed out on the band's America leg of their greatest hits tour, and lead singer Danny O' Donoghue, who formed the band with Mark in 2001, said it was down to family commitments.
He described the guitarist, a former member of the band MyTown, as "the engine of The Script."
"It's his story to tell, but yeah, I guess if I could paraphrase, his children needed a father and his wife needed a husband," Danny told Sunday World in May 2022.
"He's been the engine of The Script for such a long time, [I told him] that 'if you want to take a bit of time out for your family you are more than welcome to, and I insist on you going and doing it'.
"He took a little bit of time off. You get refreshed, then you come back with a new zest for life.
"And I believe it was the best thing that could have happened for all of us."
Mark's death was announced by the band, as a statement on their social media pages read: "Much loved husband, father, brother, band mate and friend Mark Sheehan passed away today in hospital after a brief illness.
"The family and group ask fans to respect their privacy at this tragic time."
Danny, Mark and drummer Glen Power reunited for the Irish leg of their tour, which the The Voice coach described "magic".
The band were scheduled to perform in June as they are the supporting act for P!nk for the Greater Manchester, Sunderland and Birmingham dates of her tour.
The trio were also set to be supporting Take That in London on July 1.
The Script formed in the early noughties, with Mark, Danny and Glen moving to London after signing with Sony Label Group.
They released their debut self-titled album in 2008.
Iconic tracks from the album include We Cry, The Man Who Can't Be Moved, Breakeven and Before the Worst. The album peaked at the number one spot in the UK and Ireland.
The trio have sold millions of albums and, received two Brit nominations and three Meteor Ireland Music Awards, and two World Music Awards.
Supporters and fans have rushed to pay tribute to Mark, with fellow Irish band Kodaline, saying on Twitter : "So sorry to hear the passing of Mark Sheehan!
"We had the great fortune of getting to spend time in his company over the years and was always such a lovely man! Deepest condolences to his family and his @thescript brothers."
Former Love Island presenter Laura Whitmore wrote: "Thinking of you all at this time. Mark was one of the nicest and most talented men you could meet x".