(S (S (S (NP (BASENP (NNS Helicopters)) (CC and) (BASENP (DT a) (NN warship))) (VP (VBD were) (VP (VBN dispatched) (S (VP (TO to) (VP (VB rescue) (BASENP (DT the) (NN vessel)))))))) (CONJP (COMMA ,) (CC and)) (S (BASENP (DT the) (NNS pirates)) (VP (VBD were) (VP (VBN apprehended) (PP (BASENP (NN seven) (NNS hours)) (PP (IN after) (BASENP (DT the) (JJ initial) (NN hijacking)))))))) (PERIOD .))