Yucca Valley firefighters rescued a horse yesterday that was trapped inside a trailer that came off from its tow hitch and ended up standing upright on its back doors. About 9:30 Wednesday morning, Lynn Follstad of Yucca Valley left her home towing a horse trailer with her horse inside. According to County Fire Captain Wayne Thompson, Follstad forgot to pin the trailer’s tow bar to her truck’s hitch, but according to Follstad, the pin didn’t go all the way through the hole. About a mile from her home, near the intersection of Buena Vista Drive and Warren Vista Avenue, the trailer’s tongue came out of the hitch and the trailer traveled down the road several hundred feet before it hit the berm on the side of the road. The impact made the trailer stand up upright, on its back doors. When firefighters from Yucca Valley and Yucca Mesa arrived, Boomer, the Quarter horse, was standing up inside the trailer with his head out the window, watching the activity. Firefighters had to take off the axles, cut out the metal supports on the bottom of the trailer, and cut off the wood floor from the trailer in order to remove the horse. Boomer was lucky and had only a few scratches from his ordeal.