we are just learning that the hometown celebration for sergeant bowe bergdahl has been canceled. the organizers say they're calling off the event in the interest of public safety. also tonight new details on the investigation into bergdahl's disappearance. a u.s. official briefed on the army's initial report tells cnn bergdahl left his post on other occasions. berle dall's commanders did refer to him, quote, as a good soldier. and some colleagues thought he was bored, his unit was too passive. the version is still out whether he was a captive or a deserter. the unwritten rule leave no soldier behind, whether they deserted or not. tom foreman is "outfront." >> reporter: many of the most heroic moments in military history involve american troops rescuering their own. the movie "black hawk down" was about a real battle in somalia to save helicopter crews after they were shot from the sky.