Tomorrow evening's race meeting at Tramore, the first day of their four-day festival, has been postponed until Monday as a mark of respect to jockey Kieran Kelly who died last night.
A statement from the directors of Waterford and Tramore Racecourse added: "The directors, management and staff of Horse Racing Ireland and Tramore racecourse extend their deepest sympathy to Kieran's family and his racing colleagues at this time."
A minute's silence will be observed at all five British meetings today. Racegoers at Beverley, Salisbury, Yarmouth, Hamilton and Sandown will pay tribute to the 25-year-old rider who died after sustaining severe head injuries in a fall at Kilbeggan last Friday.
Leading racing figures on both sides of the Irish Sea have spoken of their shock at Kelly's death.
Trainer Martin Pipe, who gave Kelly his first ride in the Martell Grand National on Dark Stranger in 2001, said: "He was a very talented jockey and I had a lot of respect for him. He had his first ride for us in the Grand National two years ago.
"It's a great shock and sadness for everyone. We have a lot of Irish staff here and they are all very upset as is AP (McCoy). It's a real shock for racing," he added.
Kelly was riding the Dessie Hughes-trained Balmy Native in the Joe Cooney Memorial Handicap Chase when the horse fell at the fifth fence from home. The rider, who had been with Hughes for five years and was his stable jockey, was kicked on the head and Balmy Native then rolled on top of him.
Paramedics were quickly on the scene and he was rushed to Tullamore Hospital before being transferred to Beaumont where he died yesterday evening.
Weighing room colleagues were full of praise for the rider, with Mick Fitzgerald paying tribute to "a popular lad".
"First of all my deepest sympathy goes to his family. I found out last night and I was absolutely gutted," he said. It's a big shock especially as the signs were starting to look a bit better.
"He was a lovely, lovely fellow, a really nice lad and it's even more tragic in that he was so young with his whole career and his whole life ahead of him."
Charlie Swan, the former Irish champion jockey who retired in April, started his riding career with Hughes, as did Kelly. He said: "It's heart breaking. Kieran was a real gentleman who always sought my advice, wanting to see how he could improve. He was a very good rider and I am just devastated by what's happened."
Paul Carberry learnt of Kelly's death at Gowran Park last night and was saddened to hear the news. He said: "He was a lovely lad and he was always in great form. After getting going so well last season it is particularly sad. We all felt felt it especially at Gowran last night."
Kelly's last winner came last Friday before his fall when he guided the Martin Brassil-trained Barrack Buster to success in the Foster & Allen (Mares) Maiden Hurdle. Brassil said: "It's heart breaking. He was a really nice man with a lovely manner and he was as brave as a lion."
PA