I was on my way to Auburn, IN (in the northeast corner of the state, north of Fort Wayne) last fall to visit a friend and fellow audio enthusiast. I missed the turn into his long driveway and ended up driving into Auburn before I could find a good place to turn around, and I happened upon this, standing at the entrance to an RV park:
http://www.taterworks.com/www/images/auburnsiren.jpg
It's the cleanest-looking Thunderbolt installation I've ever seen. The entire thing looks like it was made to last until World War III. The tower is steel, and the standpipe runs up through the center. The the conduit that runs to the siren tower is actually encased in the poured concrete pad. It also looks like the entire thing got a fresh coat of yellow paint. The town obviously plans to keep this thing going for a while.
Also, northern/central Indiana siren fans take note, Russiaville has a white square-horned Sentry siren. No photos yet.