(S (S (PP (IN On) (NP (NP (BASENP (NNS Presidents) (POS ')) (NNP Day)) (PP (IN in) (BASENP (NN 2004))))) (COMMA ,) (S (S (S (BASENP (NN five) (NNS workers)) (VP (VBD were) (VP (VBN killed)))) (CC and) (S (BASENP (NN four)) (VP (VBD were) (VP (VBN injured))))) (SBAR (WHADVP (WRB when)) (S (BASENP (DT a) (NN crane)) (VP (VBD collapsed)))))) (PERIOD .))