Leading Manx road racer Dan Kneen has died at the Isle of Man TT, organisers have confirmed.
Kneen, 30, sustained fatal injuries at the Churchtown section during Superbike qualifying on Wednesday.
A second rider, 36-year-old Steve Mercer from Maidstone, was injured in a later incident and taken to hospital.
Kneen was riding for the Northern Ireland based Tyco BMW team at major international road races this season in the Superbike and Superstock classes.
He rode a Jackson Racing Honda in the Supersport category.
"ACU Events Ltd wishes to pass on their deepest sympathy to Dan's partner Leanne, his family and his many friends in the road racing community and beyond," a statement from the event organisers said.
Kneen, from Onchan in the Isle of Man, set his fastest ever lap of the TT Mountain Course on Tuesday night at 132.258mph to lie third fastest in qualifying for the Superbike event.
The Manx man was Irish Superbike champion in 2014 and had previously ridden for a number of other leading teams including Northern Ireland outfits Cookstown Burrows Engineering and Mar Train Yamaha, plus Yorkshire-based Padgetts Honda.
His one international success came in the 2014 Ulster Grand Prix Superstock race. Earlier in May he won the feature race at the Tandragee 100, setting a new course record in the process.
Kneen's best TT finish was a third place in the 2017 Superstock race.
He was given a full season at Tyco BMW for 2018 after clinching second and third places in his debut with the Moneymore outfit at last year's Ulster Grand Prix.
Mechanical problems hindered his efforts at this year's North West 200, but he did secure a sixth place in the second Superstock race, his best ever result at the event.
Tyco BMW team manager Philip Neill said: "We are all numb. Our thoughts are with Dan's family and friends.
"He was a popular, hard-working lad who loved his racing and he will be sorely missed."
The Superbike practice began at 18:20 BST but was red flagged 11 minutes into the session as fire appliances were called to deal with a tree which had caught fire at the scene of the fatal crash on the approach to Ramsey.
Around an hour later the organisers announced that the session would not be re-started.