Last year's champion European sprinter Mozart died at Coolmore Stud yesterday morning. The July Cup and Nunthorpe Stakes winner suffered from non-responsive acute colitis.
"In spite of intensive veterinary treatment throughout the day and night, Mozart died at 6.15 this morning," said a Coolmore Stud statement.
Mozart also won Royal Ascot's Jersey Stakes and was placed second to Black Minnaloushe in the Irish 2,000 Guineas.
The son of Danehill ended his racing career with a disappointing 11th to Squirtle Squirt in the Breeders' Cup Sprint in October.
The action continues at Killarney this evening where Monty's Pass goes over the two and three-quarter miles of the handicap chase.
With a poor weather forecast, the trip and the going could be against Barry Geraghty's mount and the safer option could the hat-trick seeking Lights And Music.
The Jim Bolger string advertised their wellbeing at Leopardstown yesterday and the filly Mean Oiche looks an interesting contender in the second division of the handicap.
Slightly Swift ran a close third Rashay at Navan and should be a contender for the mile handicap under Pat Shanahan.
Davy Russell is a significant booking for Native Design in the bumper after that one's third to Jolly Moonbeam at Fairyhouse.