http://www.youtube.com/watch?v=QUdwnvddYe8
Filmed this today in Longview, tx...wish I could have gotten closer, but it was in a big field with a bunch of trees on one side and industrial buildings on the other...so this is the best place I could find to record. Alert starts around 50 seconds, and a train goes by around 1:45 and alert ends at 3:53. Attack starts at 5:52.