(S (S (BASENP (DT A) (ADJP (NN 7,000) (NN lb)) (NN wrecking) (NN ball)) (VP (VP (VBZ has) (VP (ADVP (RB now)) (VP (VBN been) (VP (VBN brought) (PRT (RP in)))))) (CC and) (VP (VBD demolished) (NP (BASENP (DT the) (NNS structures)) (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VBD were) (ADJP (BASENP (NN 18) (NNS inches)) (JJ thick))))))))) (PERIOD .))