(S (S (S (BASENP (DT The) (NN spill)) (VP (VBD occurred) (PP (IN on) (BASENP (NNP Friday))))) (COMMA ,) (SBAR (IN after) (S (NP (BASENP (DT a) (NN pipeline)) (PP (IN at) (BASENP (DT the) (NN port)))) (VP (VBD exploded))))) (PERIOD .))