Probably a number of accidents in those 140 miles that night. If they had no ID on them, stolen license plates, stolen car or were so badly mangled or burned as to be unrecognizable, how would anyone know who they were? There is also the possibility that they brought her back and laid her among the deceased and she is the unidentified 4 year old. Stranger things have happpened and we have to be open to new ideas.