The bombing location is just a few blocks away from the TN State Capitol building. It's closed today, but perhaps that is the real target. The bomb could be an excuse to cut off communication and power lines to it for maintenance and safety measures. If security is not on site at the capitol building (due to federal holiday), the wrong people could sneak into the building without being seen or recorded to install something there. The bombing site is a distraction to draw eyes away.

Just my speculation.

Google maps: https://www.google.com/maps/@36.1643429,-86.7828811,16.5z/data=!4m3!15m2!1m1!1s%2Fg%2F11n0jpmsx_