Since this is a DFW sirens question. Here's some info. McKinney, Texas: Whelen 4008's, one vortex, and some Omni directional ones. (Can't remember the name). Dallas: All Federal Signal SRN-2001's (Some Inactive T-Bolts) Princeton, Texas: ASC-T'121's Allen, Texas: ATI's Frisco, Texas: Whelen Vortexes...

Yes, Dallas still has a few thunderbolts. But I assume they are inactive. The person who claimed saying that one of them still runs I highly doubt. I know there is a thunderbolt near downtown though if you wish to see one that's inactive.