HERMOSA BEACH, Calif.—A six hour standoff and fire in Hermosa Beach ended when a SWAT team entered the house and found a dead person inside the garage, authorities said Dec. 25.

Hermosa Beach police officers and a sheriff’s SWAT team entered the house in the 600 block of 11th Street at about 9:30 p.m. Sunday and located a deceased person inside the garage, according to a Hermosa Beach Police Department statement.

The situation started around 3:20 p.m. Sunday when officers responded to a call of unknown trouble and a woman heard screaming near the scene, police said.

Arriving officers discovered a domestic incident occurred and a man made several threats toward a female, causing her and other family members to flee the house for their own safety, police said. The man barricaded himself inside and refused contact with officers.

Authorities evacuated nearby residences while summoning additional resources.

The Los Angeles County Fire Department (LACoFD) was also called to the scene at about 3:30 p.m., firefighter Christian Reynoso told City News Service. Firefighters proceeded with caution due to reports that the man inside the home was armed.

The fire started in the garage but spread into the single-family home and the call was upgraded to a full structure fire response at 4:50 p.m., he said.

“There was an explosion when the fire started,” Mr. Reynoso said.

Due to the possibility that an armed suspect was barricaded inside, firefighters took up defensive positions outside the home to protect surrounding structures, he said.

The family’s dog was rescued uninjured during the incident and reunited with the others who fled the house, police said.

Once the body was discovered and the house was cleared, firefighters were able to finish putting out the flames, Mr. Reynoso said.

LACoFD arson investigators planned to determine what caused the fire and the Medical Examiner’s office would confirm the identity of the deceased person.