Federal agents are sifting through the rubble of two Pueblo businesses that were leveled by an explosion that killed one person.

John Hageman of the Bureau of Alcohol, Tobacco, Firearms and Explosives said Sunday investigators still haven't determined the cause of the Thursday explosion.

Twenty-two-year-old Ashley R. Johnson was killed and seven people were injured in the blast. The Branch Inn restaurant and A Classic Boutique were destroyed.

Johnson's funeral is planned for Thursday at George McCarthy Funeral Home, located at 401 Broadway Ave.

One victim, 74-year-old Eugene "Geno" Roney, was in critical condition at a Pueblo hospital. He spent more than four hours trapped in the rubble.

Hageman says investigators have removed about 15 percent of the debris. A crane is scheduled to arrive Monday to help with the excavation.