Joshua Tree fire fighters rode to the rescue of a horse that had fallen down and couldn’t get up yesterday. Engineer Dave Faller said that a former search-and-rescue horse had gotten its legs tangled in its wooden rail fence near Broadway and Sun Mesa, and fell over. By the time fire fighters arrived about 4 p.m., the horse had managed to extricate itself from the fence, but it was so exhausted from the struggle that it was not able to stand up. Faller said the three fire fighters just “flipped it over” and the horse then stood up on its own.