The duty officer replied that security personnel at headquarters had just begun discussing the apparent hijack on a conference call with the New England regional office.
( ( The ( duty officer ) ) ( ( replied ( that ( ( ( security personnel ) ( at headquarters ) ) ( ( had just ) ( begun ( ( discussing ( the ( apparent hijack ) ) ) ( on ( ( a ( conference call ) ) ( with ( the ( New ( England ( regional office ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN duty) (NN officer)) (VP (VBD replied) (SBAR (IN that) (S (NP (NP (NN security) (NNS personnel)) (PP (IN at) (NP (NN headquarters)))) (VP (VBD had) (ADVP (RB just)) (VP (VBN begun) (S (VP (VBG discussing) (NP (DT the) (JJ apparent) (NN hijack)) (PP (IN on) (NP (NP (DT a) (NN conference) (NN call)) (PP (IN with) (NP (DT the) (NNP New) (NNP England) (JJ regional) (NN office)))))))))))) (. .)))
Nobody suspected a hijacking as the cause of loss of communication until the second plane hit.
( Nobody ( ( ( ( suspected ( a hijacking ) ) ( as ( ( the cause ) ( of ( loss ( of communication ) ) ) ) ) ) ( until ( the ( second ( plane hit ) ) ) ) ) . ) )
(ROOT (S (NP (NN Nobody)) (VP (VBD suspected) (NP (DT a) (NN hijacking)) (PP (IN as) (NP (NP (DT the) (NN cause)) (PP (IN of) (NP (NP (NN loss)) (PP (IN of) (NP (NN communication))))))) (PP (IN until) (NP (DT the) (JJ second) (NN plane) (NN hit)))) (. .)))