(S (S (S (BASENP (PRP It)) (VP (VP (VBD had) (VP (VBN been) (VP (VBN feared) (BASENP (NN yesterday))))) (SBAR (IN that) (S (NP (BASENP (NN four) (NN race) (NNS horses)) (PP (IN at) (NP (BASENP (NNP Randwick) (NNP Racecourse)) (PP (IN in) (BASENP (NNP Sydney)))))) (VP (VBD had) (VP (VBN been) (VP (VP (VBN struck) (PRT (RP down))) (PP (IN by) (BASENP (DT the) (NN virus)))))))))) (CONJP (COMMA ,) (CC but)) (S (BASENP (DT the) (NNS horses)) (VP (ADVP (RB later)) (VP (VBD tested) (ADVP (RB negative) (PP (TO to) (BASENP (DT the) (NN virus)))))))) (PERIOD .))