So I'm gonna posit a theory about the explosion in nashville.
It seems pretty likely the place that blew up was the NSA fairview VOIP monitoring site as leaked on one of the snowden maps.
I don't see any reason why the only thing on the street that would be censored by google would be the "at&t store".
Further that building is an old cold war construct meaning it's a hardened facility. Most of the switchgear would have been underground where the effects of an explosion (from the outside) would be minimized.
Evidence of this can be found in the fact that also knocked out is the 911 gear that was handling emergency calls for multiple cities around the region. Where would the logical place to be to put critical infrastructre like that?
In the hardened bunker.
Now, let's look at the timing of the explosion.
When would be the best time to try and raid a secret hardened facility?
In the middle of the week when maximum staff are on duty, or durning a christian holiday in a very christian area of the county when staffing would be minimal?
Also reference the reports of gunfire.
Now if you had a hardened government facility with secret shit in it that you absolutely didn't want to be captured by anyone might you put a self destruct mechanism in place?
If this secret hardened government facility also happened to be in a very populated area and you had concerns about potential civilian casualties when it goes off would you maybe install a warning system to tell people to get the hell away before the kaboom?