IMMEDIATELY AFTER DEPARTURE THE PILOT DECLARED AN EMERGENCY, AND THE AIRCRAFT WAS OBSERVED TURNING RIGHT, BACK TOWARD THE AIRPORT, AND LOSING ALTITUDE. THE AIRCRAFT CRASHED 1/4 MILE SE OF THE DEPARTURE END OF RUNWAY 18. THE ON-SCENE INVESTIGATION SHOWED THAT THE FUEL SELECTOR POSITION APPEARED TO BE OFF OR ON THE LEFT TIP TANK. THERE WAS STILL MOVEMENT ON THE SELECTOR TO THE LEFT, INDICATING IT MAY HAVE BEEN ON THE LEFT TIP TANK.