Board Derails News Today

Breaking news this morning on "world news now." disaster on the tracks in philadelphia. an amtrak train with hundreds on board derails without warning. a deadly accident on the nations busiest rail line. >> it is an absolutely disastrous mess. never seen anything like this in my life. >> the walking wounded, the details coming in and the tough job for investigators. our extended coverage ahead. desperate search, new developments in the search for an american military helicopter that disappeare...