(S (S (S (BASENP (DT The) (VBN relieved) (NNS passengers)) (VP (VBD left) (PP (TO to) (BASENP (NN boat))))) (SBAR (BASENP (NN 16) (NNS hours)) (SBAR (IN after) (S (BASENP (DT the) (NN fire)) (VP (VBD started)))))) (PERIOD .))