(S (S (NP (BASENP (NN Train) (NN speed)) (PP (IN at) (NP (BASENP (DT the) (NN time)) (PP (IN of) (BASENP (DT the) (NN crash)))))) (VP (VP (VBD was) (RB not)) (VP (ADVP (RB immediately)) (VBN known)))) (PERIOD .))