(CNN) -- An early morning house fire on the Fourth of July in Pennsylvania has claimed the lives of six people, authorities said.
David Kuhn and his sons Shawn, 6, and Skylar, 8, died early Thursday along with James Moore, who owned the three-story home where 14 people lived, said Capt. Fred Lenhart of the Lancaster City Fire Department.
David's wife, Crystal Kuhn, and their daughter, Mickey, died later while being treated at the burn unit at Crozer-Chester Medical Center outside of Philadelphia, according to Grant Gegwich, a spokesman for the center.
One other family member remains in critical condition there, he said Friday.
Investigators are ruling the 3 a.m. fire as accidental and say it was caused by cooking, said Lenhart, who was at the scene of the fire.
"It's never easy when we pull people out," he said. "But you know you have a job to do."
Four people who were trapped on the third floor of the home escaped through a window onto a rooftop and into a neighbor's house, he said.
Moore and David Kuhn died in the house while the two young boys died shortly after at the hospital.
Two families lived in the home, located at 115 East Clay Street in Lancaster, Lenhart said. The building had no working smoke detectors.