TOWNSEND - Four college freshmen on a spring-break excursion to the Great Smoky Mountains National Park said Wednesday that they felt lucky to be alive after they were snowed in at a shelter on the Appalachian Trail. Matthew Schultz, 19; Ivan Saldarriaga, who turns 19 today; Ryne McCall, 19; and Bryan Hendrick, 19, were rescued by park rangers and a National Guard helicopter after spending two wet, freezing nights huddled in the Derrick Knob shelter. Schultz was airlifted to the University of Tennessee Medical Center in Knoxville as a precautionary measure after falling victim to hypothermia. His three companions walked...