Arlington Park outrider Conrad Rountree, 64, died early Saturday at Northwest Community Hospital in Arlington Heights, Illinois, after suffering an apparent heart attack in the track's stable area on Friday afternoon prior to the first race.Rountree, who began working at Arlington earlier this year, was previously an outrider at Retama Park and Sam Houston Race Park. He also held a trainer's license in California, Louisiana, New Mexico, and Texas, and was licensed as a farrier in both Oklahoma and Texas.

A moment of silence was observed following the third race in the winner's circle at Arlington Park on Saturday.

A memorial service will be held at 11 a.m. CDT on Sunday in a tent next to the track kitchen on the Arlington Park backstretch.

Rountree is survived by a son, Mike, and two daughters, Liz and Jenny.