http://www.youtube.com/watch?v=ANTtR-vLKmM
This isn't my video. It's from YouTube user Ferguskeeper. An xT22, at least one other TBolt, and maybe a 2001 can also be heard.
According to the YouTube poster, the Thunderbolt heard is located at the Louisville Gas and Electric substation at the corner of Bardstown Road and Hurstborn Lane. It sounds like the old 4/5 port one that used to be at Conway Middleschool. In fact, it may even be that same siren, but in a different location. I thought we only had one of these left until now. In that user's other video from this same storm, the 4/5 port TBolt failed.