Was there some indication that this was a geocache? I didn't see any references to geocaching in the story.
The base of a bridge is a very poor choice of placement if this was, indeed, a geocache. However, I've also seen the authorities call in the bomb-squad when the container found was clearly labeled as a geocache, and the highest value target in the area was a yucca plant or two.
My personal belief is that sometimes the authorities get bored. They've spent all kinds of taxpayer cash on their bomb-squads, swat-teams, and robots, and they will use every opportunity available to manufacture a justification for those expenses and keep the cash flowing.
When common sense should prevail, what does prevail more often is the mating-call of the nanny-state: "in the name of safety, we can't take any chances."
No, there WASN'T. I used it because I have had problems geocaching.
I had one cache in a parking area adjacent to a busway. The busway is on an overpass near the lot. I would have loved to place the cache there but for several reasons put it at the base of a utility pole in the lot.
Even so it was investigated and moved once before I could explain what it was.
Then they saw people searching workers in a landscape business nearby alerted the police.
The cache is still barely active. Lots of first timers like to go there for a quick find, but I can't maintain it so I'll pull it as soon as I can get there.
The log has been waterlogged and for some reason the picture I used as a background isn't there.