(S (S (NP (EX There)) (VP (VBZ has) (VP (VBN been) (NP (BASENP (DT an) (NN investigation)) (VP (VBN launched) (PP (IN into) (NP (NP (BASENP (DT the) (NN cause)) (PP (IN of) (BASENP (DT the) (NN crash)))) (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (VP (VBN found) (PP (IN by) (NP (BASENP (DT a) (NN team)) (PP (IN of) (NP (BASENP (NNS rescuers)) (PP (IN from) (BASENP (DT the) (NNP United) (NNPS States)))))))))))))))))) (PERIOD .))