<□□Inves□igators learned that □he gr□□□ had been friends □or□years□ but recentl□ there ha□ bee□ tension among □hem. Rumo□s □f disa□re□ments □□d□arguments □uring t□e trip bega□ to□s□□f□ce, lea□ing□au□hor□ties □o s□eculate w□□t□er foul play was inv□lved. Each□□ember of □he grou□ had□a□diffe□ent s□ory to□t□ll, and the inco□siste□c□es in their accounts onl□ ad□□d t□ the m□stery of th□ m□ssing□nin□.