Officials now believe a deadly fire in Vancouver, Washington was set on purpose. Yesterday Vancouver Police and the U.S. Bureau of Alcohol, Tobacco and Firearms (ATF) were investigating a house fire early Sunday morning that took the lives of six people. On Monday, investigators said they believe the fire was arson, but did not elaborate on exactly what they believe ignited it or who may be behind it. Witnesses report hearing an explosion and seeing flames shoot 30 feet into the air from the home. Police said six bodies were found inside the burned rubble. No names or ages have been released. The Clark County Medical Examiner's Office was performing autopsies Monday to determine what caused the deaths.