Here's what I found:
"Theodore O'Connor was humanely euthanized on May 28, 2008 as a result of an injury sustained at Karen and David O'Connor's barn in The Plains, VA. The attending veterinarian stated:"
"He spooked at something while being ridden and bolted. The rider came off and the horse ran toward the barn. He got into a freak accident and slid into the side of the barn and lacerated his right hind leg about 4 inches above the fetlock on the back of the leg. It looked like a knife cut it; he severed the superficial and deep digital flexor tendons, ligaments, cut both branches of the arterial blood supply, and nerves. My experience with injuries like this are that the chances of reattaching the vascular supply and nerve supply and reattaching the tendons and ligaments is almost zero. Even if there has been a 10% chance of us being successful to recover him (from surgery) ... but with the nature of the injury, that wasn't going to happen," said Allen sadly. "Karen would have done anything for that pony."'
RH Queen O Anywhere "Sydney"
2009 Sugarbush draft