From what I read, it's a collision. The title is confusing, unless I missed something in the story. Is it too hard to simple have answered it's one or the other of the two scenarios I offered?
You know what the facts are pertaining to this terrible tragedy. You don’t need a perfectly composed title, to tell you what happened in LA. Did you see the pictures? Did you see the violent collision? Did you see the derailed cars? Did you figure out what happened? I’ve caught you stirring trouble. Now you are insulting my intelligence. Out of respect for others on this thread, I’m not going to answer you further on this board.