(S (S (S (BASENP (NN Four) (NNS people)) (VP (VBP have) (VP (VBN been) (VP (VBN injured))))) (SBAR (IN after) (S (NP (BASENP (DT a) (NN series)) (PP (IN of) (BASENP (NNS earthquakes)))) (VP (VBD struck) (NP (BASENP (NNP West) (NNP Sumatra)) (PP (IN in) (BASENP (NNP Indonesia)))))))) (PERIOD .))