An early Wednesday fire at 42009 Upper Clearfork Road has claimed a third victim.
Jennifer Harris, 33, had been flown to a Pittsburgh-area burn center but died Thursday as a result of injuries sustained in the blaze.
Two of her children, Gavin Alexander, 7, and Gracey Alexander, 6, died on Wednesday.
The blaze also sent two others to the hospital with non-life threatening injuries, and the home appears to be a total loss. Units from the Ohio Fire Marshal's office and a detective from the Harrison County Sheriff's Department were on scene investigating Wednesday afternoon, but a cause has yet to be determined.
A candlelight vigil for the victims has been planned for 8 p.m. Monday at the courthouse.