here's nbc's dan sheneman. >> reporter: on christmas day a blast shook downtown nashville >> we've come to the conclusion that an individual named anthony warner is the bomber, and he was present when the bomb went off and that he parished in the bombing. >> reporter: investigators used dna evidence to zero in on the 63-year-old warner the motive is still under investigation. police believe he acted alone. >> there's no indication presently that anyone else was involved in this crime. >> reporter: the bomb left a massive crater, more than 40 buildings and businesses damaged. >> i saw the biggest flames i've ever seen. >> reporter: nashville police officers credited with saving lives by clearing the area talked about it for the first time sunday. >> once we made contact with everyone we could and made sure that they were getting out of the building is when we started to move down. >> reporter: the blast left three people injured, no one was killed >> it was god. i'm not going to shy away from that i am a spiritual person and so i truly believe that when i do this job i'm led by that voic