(S (S (PP (IN At) (BASENP (DT the) (NN bombing) (NNS sites))) (COMMA ,) (S (BASENP (NNS wreaths)) (VP (VBD were) (VP (VP (VBN laid) (PP (IN in) (BASENP (NN respect)))) (COMMA ,) (PP (IN with) (NP (BASENP (NNS hundreds)) (VP (VP (VBG gathering) (PP (IN at) (BASENP (DT the) (NNS sites)))) (S (VP (TO to) (VP (VB mark) (BASENP (DT the) (NN silence)))))))))))) (PERIOD .))