Louisiana authorities responding to a tractor-trailer stuck on the muddy shoulder of a highway Tuesday were astounded to see what was keeping it from overturning: elephants. The truck was carrying three elephants from New Orleans to Dallas but got stuck when it pulled over onto the soft shoulder of Interstate 49 about halfway through its trip. The truck was leaning toward a ditch, and the driver led two of the elephants onto the slope between the truck and ditch and used them to help prop it up.