With no explanation, label each line with "O", "event-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
dam
was
heavily
damaged
in
the
921
earthquake
of
1999
,
which
caused
the
collapse
of
its
northern
end
.
The:O
dam:O
was:O
heavily:O
damaged:O
in:O
the:O
921:O
earthquake:event-other
of:O
1999:O
,:O
which:O
caused:O
the:O
collapse:O
of:O
its:O
northern:O
end:O
.:O