This was taken from the trainorders page today. (Author: dwalker) This is one reason for having train horns sound at grade crossings be it on track or several.

I was sitting on my bicycle at a grade crossing in downtown San Diego, watching a freight train go by.
Sometimes it takes the train a long time to pass all the signals and work its way around the Coaster, Amtrak, and the Trolley, and this was one of those days.
As a result, lots of pedestrians started to accumulate on both sides of the crossing.
The train stopped again, and three pedestrians crawled under a tank car and ran across the other two tracks to my side. I couldn't believe it!
They then proceeded to encourage others to follow them. Some of us yelled at them 'Don't do it!'
Finally, one young man started to crawl under the tank car, just as the train started again! He did a quick roll just before his leg got run over.
He got up, pale and shaken, and staggered across the other two tracks, just as a trolley came by at speed. He barely missed getting hit by the trolley and
got to my side of the crossing. He sat down on the sidewalk, visibly shaken. I was going to say something to him at this point, but I think he got the idea.

Time for Operation Lifesaver again?