Updated

Investigators have not been able to determine what caused a fire that killed four family members in South Carolina, but they say it doesn't appear to have been intentionally set.

State Law Enforcement Division spokesman Thom Berry said in a Thursday news release that investigators couldn't pinpoint a source for Tuesday's blaze that killed a mother, father and two children.

Lexington County Coroner Margaret Fisher said smoke inhalation caused the deaths of 42-year-old Scott A. Kelly, 34-year-old Amanda G. Kelly, and two of their children, 9-year-old Elizabeth M. Kelly and 10-month-old Judah A. Kelly.

Two other children and their grandmother were able to get out of the home west of Columbia after the fire started around 1 a.m.