(S (S (BASENP (NNP Friday)) (VP (VBZ marks) (NP (BASENP (DT the) (JJ 50th) (NN anniversary)) (PP (IN of) (NP (BASENP (DT a) (NN mining) (NN disaster)) (SBAR (WHNP (WDT which)) (S (VP (VP (VP (VBD occured) (PP (IN in) (BASENP (NNP Lanarkshire) (COMMA ,) (NNP Scotland)))) (PP (IN on) (NP (BASENP (NNP September) (NN 18)) (COMMA ,) (BASENP (NN 2009))))) (COMMA ,) (S (VP (VBG killing) (BASENP (NN 47) (NNS miners)))))))))))) (PERIOD .))