Police have now confirmed that one of the two pedestrians hit by a car outside Wetherby Racecourse has died.
The driver of the car involved has also been arrested on suspicion of causing death by dangerous driving.
A 65-year-old man died at the scene. The other man, aged 52, remains in hospital with serious injuries.
A Mercedes collided with them close to the racecourse entrance after veering off the road in the incident at around 5pm, shortly after the day's race meeting had finished.
A witness said:-
"We left about an hour after the last race in a taxi. We went past an ambulance, and I saw one man receiving CPR on the grass verge near the roundabout entrance to the races
"It did not look good at all. I really hope he’s okay. The taxi driver said there were two men receiving attention from the paramedics. Put a real dampener on a good day."
West Yorkshire Police said:
"At 5:08pm yesterday police were called to the incident on the B1224 York Road next to the racecourse.
"A silver Mercedes C220, which was travelling west towards Wetherby town centre, had been involved in a collision with two pedestrians who were part of a group walking along the road in the same direction.
"A 65-year-old man received emergency treatment at the scene but was pronounced dead a short time later.
"A 52-year-old man was taken to hospital by air ambulance and remains in a critical condition.
"The Mercedes driver, a 40-year-old man, was arrested on suspicion of causing death by dangerous driving. He was later released under investigation.
"A road closure was put in place while the scene was examined and reopened shortly before 10pm.
"Anyone who witnessed the collision or the circumstances leading up to it is asked to contact West Yorkshire Police Major Collision Enquiry Team via 101 quoting 13190563820."