As the weekly photo fun showed, kids and trains can result in accidents--though that one wasn't the kid's fault.  One precaution we can take if a kid might run the train (or some adults i know) is to set teh decoder so that the loco's maximum speed is suitable for the track conditions--almost all kids have a natural instinct to open a throttle wide.  (Having a throttle in your own hand, with a finger over the track power button is not a bad plan, either; the yard doesn't need to be switched at 100 MPH, and a Climax running at 40 mph isn't right either...)

I see kids as the next generation of the hobby--but we can also take steps to insure that the current generation's toys are still in one piece.  And the best steps are ones that are invisible to the kid, especially if it's a young kid, so they only have to remember a few basic rules.

At the Volusia County train show in Florida, one club lets kids run train on the layout--all the kid needs to know is how to stop and go, and that a red signal means stop.  They loved it--and obeyed signals better than the adults.  No need to worry about "Don't go too fast," though kids that knew how things worked did have to be told not to back up...

Having durable cars on the child's consist helps, too.