Several years ago I seem to remember that someone was sabotaging the tracks in Britian. There were several accidents. I thought from the beginning that this MIGHT have been a terrorist incident. Remember, their strength is that they strike where we are not prepared. Especially in Florida I am suspicious, FL seems to be a good place for terrorist cells to operate, we have such a high transcient rate here.
That said, if this WAS a terrorist incident, I would think they would have claimed responsibility by now. Terrorism is only "fun" when you let your victims know it was you.