With no explanation, label each line with "O", "organization-government/governmentagency", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
cause
of
the
accident
is
under
investigation
by
the
National
Transportation
Safety
Board
(
NTSB
)
.
The:O
cause:O
of:O
the:O
accident:O
is:O
under:O
investigation:O
by:O
the:O
National:organization-government/governmentagency
Transportation:organization-government/governmentagency
Safety:organization-government/governmentagency
Board:organization-government/governmentagency
(:O
NTSB:organization-government/governmentagency
):O
.:O