Updated information being reported states that the bomb-laden RV parked next to the AT&T building in Nashville broadcasted an evacuation order over a loudspeaker, and then broadcasted a 15-minute countdown before the bomb exploded:
Then, she said, she heard a repeated warning she said came from the RV parked outside her building.
She recalled hearing the announcement warning of a bomb and to evacuate. Then, it started counting down to the explosion, she said.
Williams said she, her spouse and family left the lofts in their pajamas. She took her cat Mavis but left her valuables behind.
They headed to Nissan Stadium and waited. When they didn’t hear an explosion, they headed back. They were at Second Avenue and Broadway when they saw a fireball fly over the AT&T building on Second Avenue.
“Whoever did it did give fair warning,” Williams said.
This fact along with the timing of the bomb (early Christmas morning) and its placement (an area of Nashville unlikely to have many people around at that time) seems to indicate that the bomber wanted to avoid casualties to the extent possible. Any motive at this point would just be speculation, but it makes for a strange situation compared to other bombings.