(S (S (S (BASENP (PRP It)) (VP (VP (VBZ is) (RB not)) (VP (VBN known) (SBAR (WHNP (WHADJP (WRB how) (JJ many)) (NNS people)) (S (VP (VBD were) (PP (IN on) (PP (NNS board) (BASENP (DT the) (NN plane)))))))))) (CONJP (COMMA ,) (CC but)) (S (BASENP (DT no) (NNS injuries)) (VP (VBP are) (VP (VBN reported))))) (PERIOD .))