Nashville 2nd Street Explosion Street View

What is in the AT&T building on 2nd Street? Why is the front of the building grayed out on g-maps street view? Are there government agencies using that space? Research the warning symbols posted on the street near the RV/bomb detonation. Coincidence? Hefty explosion for a propane tank on an RV... Did it even come from the RV or did it come from a building? PA system was clearly on the vehicle warning residents to evacuate, but was it the source. What was the target and why? Setup to destroy the target without innocent human casualties... a soft hearted madman, or well-planned operation? Christmas Day 2020