Cops stated that they were responding to a shots fired call, per
https://youtu.be/Fq_wMFroQgc?t=2h10m
Also, reporter stated that they were already on their way [to downtown nashville] "for another reason":
https://youtu.be/Fq_wMFroQgc?t=2h11m30s
Also, the reporter states that STATE TROOPERS WERE ALREADY THERE, even though the reporters were ALREADY ON THEIR WAY WHEN THEY HEARD THE EXPLOSION:
https://youtu.be/Fq_wMFroQgc?t=2h11m35s
However, there are now indications of "blown in" (photo), but the explosion video still shows NOTHING LIKE AN RV