Police believe an explosion in downtown Nashville that hospitalized three people and damaged 20 buildings was an "intentional act." 

Police responded to reports of a suspicious vehicle parked outside the AT&T building just before 6 am on Christmas morning. After an officer alerted the department's hazardous devices unit, which was en-route, a "significant explosion" happened. Nashville Mayor John Cooper revealed that three people were sent to the hospital with injuries, while 20 buildings were damaged. 

Video of the aftermath shows buildings decimated, and people say the sound of the explosion could be heard for miles. Mayor Cooper added that the downtown area will be "sealed off" for further investigation to make sure everything is "completely safe."