The explosion was apparently connected to a gas leak that happened after a private contractor was digging on the property without first checking with the gas company, according to SoCalGas officials.
Three of the injured people were firefighters and the other 12 were civilians, fire department officials said.
SoCal Gas says one employee was killed in the explosion and another was transported to the hospital with injuries.
"Today SoCalGas crews responded to reports of a damaged natural gas line & shortly after our crews arrived, there was an explosion," SoCalGas wrote on Twitter. "Sadly, one of our employees was fatally injured and others harmed. Our thoughts are with the families & first responders impacted."
Authorities were first called to the home in the 23500 block of Wooden Horse Trail just before 11 a.m. on a report of a gas line rupture. Firefighters responded and SoCalGas was on the scene by 11:23 a.m., fire officials said.
The explosion was reported at 12:10 p.m.
"It shook the house. The windows sounded like they were going to break. The walls shook," said neighborhood resident Rebecca Byrd. "I mean, everybody was terrified."
Additional firefighting units and paramedics were called in as the house burst into flames and heavy smoke poured into the sky.
SoCalGas said it appears a contractor had been working on the home and had failed to call 811 to check for gas lines before digging.
"No matter what you're doing, if you're digging, please call 811," a SoCalGas official said.
Clinton Keith Road was closed from Smith Ranch to Nutmeg.
Neighbors said the home was recently sold, and the new owners were doing some renovations. It's unclear if the residents of the home are among the injured, but officials said everyone has been accounted for.
Residents of neighboring homes were evacuated. Officials did not have a timeline as to when they would be allowed to return to their homes, but an evacuation center was established for them at Vista Murrieta High School at 29251 Clinton Keith Road.