After their owners inadvertently left them behind in Yellowstone National Park, Louie, a 4-year-old golden retriever, and Nipsy, a 3-year-old longhair cat, were killed within minutes of beginning their heartwarming journey home, sources reported Monday. 'It looks like right after leaving the campsite they fell off a cliff and died upon impact with the highway below,' park ranger Ken Hinkley said after discovering their barely recognizable bodies, which had been partially eaten by a cougar the pair likely would have outsmarted with adorably clever teamwork had they survived. 'After that, it appears their carcasses were run over by a tractor-trailer, probably operated by a gruff but kindhearted truck driver who no doubt would have given them a lift. Poor little guys. Had to toss 'em in a ditch.' Louie and Nipsy's family reportedly gave up hope immediately, and have already purchased a new kitten and puppy whom they love very much. 