Monday's final under tack show for Keeneland's April sale of 2-year-olds in training was marred by a fatal injury to a Hennessy colt. Consigned by Mike and Britt Mulligan's Leprechaun Racing, the colt broke down on the main track after working a quarter mile in : 21. He suffered a compound fracture of the left front fetlock and was euthanized.Produced from the unraced Slew o' Gold mare Scivolina, the colt had been purchased for $90,000 by Leprechaun at last year's Keeneland September yearling sale and was owned by a Leprechaun pinhooking partnership. During the auction's first under tack show on April 7, he worked an eighth of a mile in :10 2/5."He was a very nice horse, and he was doing everything perfect," Mulligan said. "He worked :21 flat, so he obviously had a lot of talent. It's just one of those freak things; it's unfortunate that it happened."I can't say anything bad about the track," he continued. "It's fast. But when the horses are going by, you can't hear them, so it's got a good cushion to it. If I had to do it all over again, I would work the horse. I'm not second-guessing my decision. Horses are working fast today; it's April. He was fit and ready to go a quarter."The colt's rider, Tracy Brown, escaped injury."She's fine and back in the saddle," Mulligan said.Said Geoffrey Russell, Keeneland's director of sales: "We're very sad it happened. But we're glad that everything got taken care of very quickly and in a timely manner. And we're glad the rider is all right. The track is safe and fast."It was a beautiful day in Central Kentucky, with sunny skies and warm temperatures..The fastest quarter-mile time of :20 3/5 on the main track was posted by a Forestry -- Northern Sanction colt, consigned by Niall Brennan Stables. A $95,000 buy-back at last year's Fasig-Tipton Saratoga select yearling sale, the colt is a half-brother to graded winners Regal Sanction (by Regal Classic) and Nonies Dancer Ali (by Danzatore)."He went :10 1/5 last week, but we felt like he didn't get to show his best," Niall Brennan said. "I know that sounds silly, but he didn't get into his rhythm. It was a muddy track."A Forest Wildcat colt consigned by Brennan was the second-fastest worker at a quarter, covering the distance in :20 4/5. Produced from the stakes-winning Star de Naskra mare Starita, he is a half-brother to Canadian champion Honky Tonk Tune (by Cure the Blues). Kentucky bloodstock agent Mike Ryan purchased the colt for $140,000 at the 2002 Keeneland September yearling auction.Four horses were clocked in :10 1/5 on the main track, sharing the fastest time for an eighth of a mile. They were a Dance Brightly -- Bright Image colt, an Old Trieste -- Heat Is On filly, a Forest Wildcat -- Malley colt named Wildcat O'Malley, and a Silver Ghost -- Cerita filly.A Good and Tough--Tarnished Gold colt turned in the fastest three-furlong time of :33 1/5 on the main track. Consigned by Tony Bowling and Bobby Dodd, he ranked among the fastest workers at a quarter mile on April 7 with a clocking of :21 1/5.Workouts were also held on the turf, where a Stravinsky--Audra filly had the fastest time of :10 for an eighth. A Lear Fan--Bin Sweet colt named Frejolito and an El Prado--Le Gueriere colt shared the fastest clocking for a quarter of :21.The sale is scheduled for Tuesday, beginning at 1:30 p.m. (EDT).