Jockey Mark Pace died Sunday of injuries he suffered during the first race at Blue Ribbon Downs in Sallisaw, Okla. He was 58. \nPace was taken to Sequoyah Memorial Hospital in Sallisaw after he was thrown from his mount, Reep What You Sow, who hit the rail on the backstretch during the 5 1/2-furlong maiden claiming race for fillies and mares. Pace was pronounced dead at 12:52 p.m., according to Jerry Green, the chaplain based at Blue Ribbon. \nAn investigation into the incident is underway, said Tino Rieger, the executive director of the Oklahoma Racing Commission. \n"It's one of those things you have to do as a commission," he said. "It's a tragic event. Our condolences go out to the family." \nGreen on Monday was working with the chaplaincy staff and a local funeral home to make contact with Pace's relatives. Pace is survived by five children, all of them residents of the state of Washington except for one son, who lives in New Jersey.\nReep What You Sow was a pickup mount for Pace. He was new to the Blue Ribbon meet, having come up from a farm in south Texas in the last couple of weeks. Green said services for Pace will be held at the track, with a date to be determined. Pace is believed to have just recently resumed riding after a 10-year hiatus. \nBlue Ribbon officials canceled the remainder of its card Sunday upon learning of Pace's death.