NASHVILLE, Tenn. (AP) — Federal agents have converged at the home of a possible person of interest in the explosion that rocked downtown Nashville on Christmas morning. Investigators are scouring hundreds of tips and leads in the blast that damaged dozens of buildings. More than 24 hours after the explosion, a motive remained elusive as investigators worked round-the-clock to resolve unanswered questions about the mysterious blast. The explosion took place on a mostly deserted street on a sleepy holiday morning and was prefaced by a recorded warning advising those nearby to evacuate. Officials have been searching a home in Antioch in suburban Nashville.