Pine Ridge, SD – The Bureau of Alcohol, Tobacco, Firearms and Explosives has determined that the duplex explosion in Pine Ride was an accident, caused by a leaking propane line.

Four people were killed Thursday afternoon when the duplex exploded. The victims’ names have not been released. A man and woman shared one side of the duplex and two women were in the other home.

The agencies involved in the investigation include the Oglala Sioux Tribe Department of Public Safety, Bureau of Indian Affairs, Federal Bureau of Investigation, State Fire Marshal’s office and ATF.

According to an ATF release, more information about the explosion will be made available in the next few days.