I agree. I once knew some folks in LPD. If I had not lost contact with them, then I could ask them for the "inside scoop" on this story.
The highway over Hoover Dam was closed for several hours to investigate a "suspicious" object---you could tell from the TV camera shot it was a piece of about 2-inch angle iron about two feet long--it was a clamp of some sort that fell off a highway dep't centerline painting truck--