Arcadio Lopez Castrejon, a 41-year-old Isla Vista resident, and his seven-year-old son, Fabian Arcadio Lopez, were killed early Friday morning after a fire raged through their Picasso Road apartment.

Leonor Lopez, 41, the mother, is listed in serious condition at the intensive care unit of Santa Barbara Cottage Hospital. Christian Lopez, the couple’s 5-year-old son, is in a pediatric ICU unit at the hospital and listed in critical condition. A hospital spokesperson said Christian was receiving treatment for severe burns.

Officials have not yet determined the cause of the fire, and said it could take a few days because of the extent of the damage.

Santa Barbara County Fire Dept. responded to 9-1-1 calls from the apartment complex at 6651 Picasso Rd. around 3:30 a.m. on Friday morning. Approximately 60 residents were evacuated from the 18-unit complex, and the fire was contained to the family’s apartment.

Castrejon was pronounced dead at the scene. Firefighters and rescue workers attempted to resuscitate Fabian, but he was pronounced dead at the hospital.