LYNDORA — Heavy flames and smoke early Saturday morning forced a young man to climb out an upstairs window and then jump from a porch roof at his family’s burning house on Bessemer Avenue, authorities said.

Chance Reott, 19, was injured in the daring escape, said Chief Dexter Kiebler of the Lyndora Volunteer Fire Department, and he was later flown by medical helicopter to a Pittsburgh hospital.

The man’s parents, Ronald and Gail Graham, who own the house, and his 13-year-old sister also were at home but they got out uninjured, Butler Township police said.

The apparently accidental fire about 2:50 a.m. destroyed the two-story house at 105 Bessemer Ave., and killed the family’s dog.

Investigators believe Ronald Graham was awakened by the fire that started in his first-floor bedroom.

“He looked up and saw the top of the couch in the bedroom on fire,” said police Lt. John Hays.

Graham immediately rushed to the living room where his wife had fallen asleep. He got her up and then went to alert the couple’s children.

“He went upstairs and beat on his son’s door,” Kiebler said. “It was locked, but he thought he heard (Reott) get up and then he went to his daughter’s room.

He got into his daughter’s upstairs bedroom, awakened her and helped her down the stairs.

The fire’s intensity prevented Reott from taking a similar escape route.

“The smoke was overwhelming,” Kiebler said, “so he had to climb out the window onto the porch and jump off the porch roof.”

Butler Ambulance Service paramedics were the first emergency responders on scene and immediately treated Reott. He was taken to Butler Memorial Hospital and later flown to an unknown Pittsburgh hospital.