It's interesting how much little actual information is reported on this in the press. This is the TLDR breakdown:

A) The bomb was in an RV, it warned people to evacuate and had a fifteen minute countdown.

B) It is clear that human lives are not the target.

C) It took out an AT&T comm building and a regional hub. Fairly clear that is the target. Severe damage and a partial collapse of one building is reported.

D) AT&T owns CNN, by the way.

E) There is tangible information that there are others who want to attack communication and power infrastructure across the country.