After 11 days of intensive investigation, a collective portrait
has begun to emerge of the men who guided three planes into the
World Trade Center and the Pentagon and crashed a fourth in an
empty field in Pennsylvania.  It is sketchy and incomplete, but
its disparate pieces show a group of seemingly well-educated
young men who slipped into the country and settled into bland
suburban lives while they gained just enough training as pilots
to take control of a passenger jet in midair.  While American
officials have blamed Osama bin Laden for the attacks, they are
still struggling to connect him directly to the plot.
Investigators believe there were many more conspirators, but
despite the efforts of thousands of law enforcement and
intelligence agents, the authorities have arrested only a
handful of suspects in the United States.  From interviews and
confidential law enforcement documents, it appears that the
hijackers lived at once secretly and in the open, taking
advantage of the anonymity and freedom of a soc