(S (S (S (NP (BASENP (DT A) (JJ fierce) (NN storm)) (PP (IN on) (BASENP (NNP Sunday)))) (VP (VBD resulted) (PP (IN in) (BASENP (JJ massive) (JJ 18-foot) (NNS waves))))) (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VP (VP (VBD split) (BASENP (DT a) (JJ Russian) (NN oil) (NN tanker))) (PP (IN in) (BASENP (NN two)))) (CC and) (VP (VBD sank) (NP (BASENP (NN two) (JJ Russian) (NNS freighters)) (ADJP (JJ nearby)))))))) (PERIOD .))