Four children and two adults killed in a western Pennsylvania house fire died of acute smoke and fume inhalation, according to autopsy results released Sunday.

Investigators have not yet identified the cause of Saturday's fire, which killed a recently married woman, her four young children and her disabled father-in-law.

The Allegheny County medical examiner's office identified the victims as Ronald Egenlauf Sr., 55; Hope Jordan, 27; Dominic Jordan, 7; Autumn Jordan, 6; Serenity Jakub, 3; and Victoria Jordan, 2.

Previously, family members had identified the youngest victim as Victoria Jakub. They also gave Ronald Egenlauf's age as 56.

The sole survivor of the McKeesport blaze, 23-year-old Keith Egenlauf, remained in critical condition at UPMC Mercy hospital, a nursing supervisor said. He was burned over 55 percent of his body, according to his aunt, Donna Ackerman.

Keith Egenlauf and his wife initially managed to flee the flames, but returned to the burning two-story house in an effort to save the others, relatives said.

Father and son had lived in the yellow wood-frame house for about 10 years, Ackerman said. Ronald Egenlauf had been paralyzed from a stroke that he suffered about six years ago.

Keith Egenlauf and Jordan were married Dec. 7, according to their Facebook page.

McKeesport is about 10 miles southeast of Pittsburgh.