Now CBS News Learning that police have a person of interest or persons of interest in connection with the explosion that rocked Nashville on Christmas Day. Federal investigators This today. Stay there, searching for clues in the area popular with tourists and Nashville after an RV exploded there early yesterday. The blast, damaging dozens of buildings and injuring three people, and police say this blast was no accident. The quiet of Christmas morning shattered just after 6 30, a chilling message blaring from the RV seconds before it exploded. The blast could be felt miles away. It shattered windows, shook buildings and sent a tower of black smoke high above downtown Nashville. That is CBS News correspondent Moola Langi in Nashville. Police also confirmed they found what could be human remains near that RV that exploded. President