This is a dam not too far from where I live.
I visited not too long after 9-11. Since I was a kid, we had always walked across the dam and looked down that long face, but this time this little sign was there along with a very diminutive road block.
I walked a few feet past the sign and WHOOM, a shouting screaming official showed up out of no where to give me a great deal of what ever. Since this is as rural as you can get, it was amazing how quickly he arrived and breathless, almost.
Dumb, yea.
If the dam were to be bombed away, it would flood some farm land, not any population center at all.
Someone said that what we have lost is good sense.
A bridge washed out a year or two ago, and now I can walk and drive across the dam, since it is the only route to a campground and the headquarters for the dam managers.