Big Brown backed up his trainer’s boasts with an explosive finishing kick and won the Kentucky Derby on Saturday.

But the cheers of the crowd were cut short when the filly Eight Belles, who finished second, was euthanized on the track minutes after the race with a fatal injury.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

LOUISVILLE, Ky. (AP) _ Big Brown won the Kentucky Derby on Saturday, living up to his status as the pre-race favorite.

Filly Eight Belles was second, but she broke down as the 20-horse field galloped out past the finish line.

She was later euthanized on the track.