Race organisers the Loughshinny Motorcycle Supporters Club announced on Saturday evening that Dunlop, a regular at the Isle of Man TT and North West 200, had succumbed to injuries suffered in an accident earlier in the day.
Dunlop was competing in practice for the County Dublin event at the time of the crash. It’s understood that the Ballymoney rider was competing in open practice on his Temple Gold Club-backed Yamaha R1 when he crashed near Sam’s Tunnel on his third lap around 17:00 BST.
The session was immediately red flagged so that medics and Gardai could attend the scene, but he was pronounced dead soon after.
He had previously won races at both the North West 200 and Ulster Grand Prix, and secured nine podium finishes at the Isle of Man TT since his debut in 2006, with a best result coming in the form of a second place in the 2016 TT Zero. He started racing back in 2000 and claimed 108 victories in Irish National Road Racing, including 15 wins around the Skerries circuit.
Dunlop won four times at the North West 200, the most recent of which came in 2014, and claimed seven wins at the Ulster GP. He also has the notable accolade of competing in his one and only 250cc world championship race in the last ever grand prix at Valencia in 2009 before the class changed to Moto2.
The Northern Irishman, whose brother is 18-time TT winner Michael Dunlop, did not compete at this year’s event after deciding to withdraw to return home and be with his pregnant girlfriend Janine due to what he later revealed to be concerns about her 20-week scan, though the situation had since improved and the couple were looking forward to the birth of their second child together.
Michael is also due to compete at the Skerries 100 this weekend, with both named in the field for the Martin Finnegan Memorial superbike race, the richest event in Irish road racing that honours the late Lusk rider who died 10 years ago at Tandragee.
The Dunlop brothers were also competing at the North West 200 in 2008 when father Robert suffered a fatal accident during practice. Their uncle, the legendary Joey Dunlop, won 26 Isle of Man TT races before his death in an accident while racing in Estonia in 2000.
Susan Plunkett, clerk of course of the Loughshinny Motor Cycle Supporters Club, said in a statement: "The Loughshinny Motorcycle Supporters Club, organisers of the Skerries 100, deeply regrets to announce that competitor William Dunlop of Ballymoney, Co. Antrim, has passed away following injuries received in a tragic accident that occurred during practise which took place today 7th July 2018.
“The Loughshinny Motorcycle Supporters Club extends their heartfelt sympathy to William Dunlop's family and friends. Our thoughts and prayers are with them at this very sad time."
Dunlop has ridden for a number of leading teams during his career, which include the Tyco Tas Racing team, Milwaukee Yamaha and Wilson Craig Racing.
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