(S (S (NP (NP (DT A) (QT (DQL ``) (NP (ADJP (RB well) (JJ informed)) (NN source)) (DQR ''))) (VP (VBN quoted) (PP (IN by) (BASENP (NNP French-language) (NN daily) (NNP Le) (NNP Soir))))) (VP (VBD suggested) (SBAR (IN that) (S (BASENP (EX there)) (VP (MD might) (VP (VB have) (VP (VBN been) (NP (BASENP (DT an) (JJ electrical) (NN failure)) (PP (IN in) (BASENP (DT the) (NN signalling) (NN system))))))))))) (PERIOD .))