The New York Center controller and manager were unaware that American 11 had already crashed.
( ( ( ( The ( New ( York ( Center controller ) ) ) ) and ) manager ) ( ( ( were unaware ) ( that ( ( American 11 ) ( ( had already ) crashed ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNP New) (NNP York) (NNP Center) (NN controller)) (CC and) (NP (NN manager))) (VP (VBD were) (ADJP (JJ unaware)) (SBAR (IN that) (S (NP (NNP American) (CD 11)) (VP (VBD had) (ADVP (RB already)) (VP (VBN crashed)))))) (. .)))
The controllers soon found out the plane had crashed.
( ( The controllers ) ( soon ( ( ( found out ) ( ( the plane ) ( had crashed ) ) ) . ) ) )
(ROOT (S (NP (DT The) (NNS controllers)) (ADVP (RB soon)) (VP (VBD found) (PRT (RP out)) (SBAR (S (NP (DT the) (NN plane)) (VP (VBD had) (VP (VBD crashed)))))) (. .)))