The Man Who Knew (full documentary) | FRONTLINE When the Twin Towers fell on September 11, 2001, among the thousands killed was the one man who may have known more … Alien Conspiracies frontline 911 documentary frontline the man who knew john o'neil documentary john oneil story osama bin laden documentary the looming tower documentary watch 911 documentary online watch the man who knew 44355 views 0 / 0