(S (S (BASENP (DT A) (NN police) (NN spokeswoman)) (VP (VBD added) (SBAR (IN that) (S (S (BASENP (DT the) (NN death) (NN toll)) (VP (MD could) (VP (VB rise)))) (SBAR (IN as) (S (BASENP (NN rescue) (NNS workers)) (VP (VBP continue) (S (VP (TO to) (VP (VB search) (PP (IN for) (BASENP (NNS victims))))))))))))) (PERIOD .))