Nashville bombing: 'Not your typical type of crime scene' may take years to investigate

It could be months or longer before the world learns the motive in the downtown Nashville Christmas morning bombing, an FBI spokesman said Friday.

"Bombing investigations can take years," said Darrell DeBusk, an FBI spokesman based in Tennessee.

Local and federal law enforcement say 63-year-old Anthony Quinn Warner blew up a city block with an RV containing unidentified explosives about 6:30 a.m. on Second Avenue North outside an AT&T switch facility. The bomb injured at least three people, damaged dozens of downtown buildings and crippled telecommunication systems throughout the southeast for days.