Firefighters found his 76-year-old stepmother inside clinging to life. She was taken to UC Davis Medical Center where she died. In the back of the duplex was the lifeless body of his 87-year-old dad.
The elderly couples' pet dog and cat also died.
"Right now I'm just kind of numb," Frizell said.
The shock of the deaths has crept through the neighborhood.
"They were very nice people, very quiet, very cordial," said neighbor Oscar McKneely.
The Sacramento Fire Department said one of their own was even injured. Minor burns to a firefighter's hands and knees sent him to the hospital, but spokesperson Chris Harvey said the firefighter was released and is doing well.
While investigators figure out how and where the fire started, and if the home had working smoke detectors, Frizell said he worried about his family being alone in that home. He said the health of his stepmother and his wheelchair-bound father was going downhill.
"I would've had more peace of mind if they were in a (nursing) home but they didn't want that," he said.
But there is one thing Frizell takes comfort in, "What I have right now is knowledge they're together."