- Associated Press - Wednesday, February 12, 2014

LEBANON, Tenn. (AP) - Authorities investigating a deadly house explosion in Middle Tennessee continue searching the site for evidence.

The Tennessee Bureau of Investigation said an unknown package exploded at the home in Lebanon. The agency said 74-year-old John Setzer was killed, and 72-year-old Marion Setzer was injured. She was in critical condition at Vanderbilt University Hospital on Tuesday.

TBI Director Mark Gwyn said investigators will be at the site day and night to resolve the case quickly.

Agents from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives were also investigating the blast that occurred Monday at the home on a rural cul-de-sac. Crews in white hazardous materials suits were walking around the property, and official vehicles filled the yard of the red brick two-story home with white dormers on Tuesday.