(S (S (NP (BASENP (NNP Sheryl) (NNP Sandberg)) (PRN (COMMA ,) (BASENP (NNP Facebook) (NNP Chief) (NNP Operating) (NNP Officer)) (COMMA ,))) (VP (VBD was) (VP (VBN supposed) (S (VP (TO to) (VP (VB travel) (PP (IN on) (BASENP (DT the) (NNP Asiana) (NN flight))))))))) (PERIOD .))