Anthony Quinn Warner was responsible for the Christmas morning explosion that rocked downtown Nashville, officials said Sunday, and he died in the blast. Investigators matched human remains found at the scene with Warner’s DNA, confirming suspicions that he blew himself up in a recreational vehicle, Tennessee Bureau of Investigation Director David Rausch told reporters. Law enforcers said they were investigating a motive. Authorities had assembled Saturday at Warner’s home in Antioch, Tenn., about 10 miles southeast of the explosion site. Several neighbors described seeing an RV similar to the one that blew up Friday morning, in the backyard of the...