I have read rumors about both male or female dying. Tom would be fine with me too. I don't like his character much. I suppose the fire could be set by Dave to kill Mike and we see his doctor rusing to the scene too late to stop Dave. That would be the end of the mystery and that makes sense. But we see Mike in the preview holding Susan back. If the fire was set to kill Mike, one might assume Dave tied him down in some way to prevent his escape.
It does not make sense to bring Julie back to kill her, no. But if you want to cram in as much drama as you can why waste the opportunity to have a character leave under normal circumstances?