By Sam Turner For Mailonline
Published: 11:01 BST, 13 August 2017 | Updated: 11:03 BST, 13 August 2017
William Buick was last night stretchered from the track at Arlington when his mount Permian suffered a fatal injury crossing the line in the Secretariat Stakes.
The Mark Johnston-trained colt had to be put down when the three-year-old son of Teofilo sustained a broken left leg in the mile-and-a-quarter Grade One at the Illinois circuit.
Permian unseated Buick soon after the partnership crossed the line in last place and the British rider was taken to Northwest Community Hospital complaining of back pain which transpired to be a fractured T12