(CNN) -- The San Mateo, California, coroner's office Wednesday announced the identification of three family members killed in the September 9 gas pipeline explosion in San Bruno.
The announcement brings the death toll for the explosion and subsequent fire to seven.
Lavonne Bullis, 85; her son, Gregory Bullis, 50; and his son, William James Bullis, 17, all of the same address, died in the blaze, the office said.
The elder two were identified with the help of DNA testing, and William Bullis was identified through examination of remains, the coroner said.
Jacqueline Greig, 44, and her 13-year-old daughter Janessa also were killed, as were Jessica Morales, 20, and Elizabeth Torres, 81.
The blast blew in the doors of a grocery store a quarter-mile (400 meters) away, and the explosion and resulting fire injured 52 people and destroyed 37 homes. The explosion blew a 28-foot section of a gas pipeline 100 feet in the air. Federal investigators are looking at the condition of the pipe.