At least five barns were damaged and horses were running loose at Churchill Downs, home of the Kentucky Derby, after a powerful storm spawned tornadoes.
Officials have no immediate reports of injuries to humans or horses.
The National Weather Service said radar was tracking a confirmed tornado near the famed track and the University of Louisville campus about 8.10pm on Wednesday (1010 AEST Thursday).
Though no races are run on Wednesdays, there was simulcasting of races elsewhere, so people may have been there, said track president Kevin Flanery.
Churchill Downs spokesman Darren Rogers said at least five barns had roof damage and the chapel was hit. The barn damage was on the backside of the track where workers live in the dorms, Flanery said.
The iconic twin spires above the clubhouse overlooking the finish line were apparently not damaged, Flanery said.
“Clearly we’ve got several barns with significant damage and we’re just trying to make sure people and the animals are safe first,” Flanery said.
Security guards were turning away reporters, citing danger from the loose horses.
The Kentucky Derby has been run for more than 130 years at the track. It is the first leg of the Triple Crown, America’s big three horse races.
The track has a capacity to handle a crowd of about 160,000 for the Kentucky Derby.
Storm sirens wailed in Kentucky’s largest city as multiple tornado warnings were issued as the storm went through.
AP AAP TURF