Hannah and Ethan were last seen on Saturday. Their mother, Christina Anderson, 44, was found dead inside a burned out home in the rural community of Boulevard, near the Mexico border.
Officials determined the mother was murdered, but have not yet released details of her death due to the ongoing investigation.
The San Diego County Sheriff’s Department said a child’s remains were also found on the scorched property in the 2000 block of Ross Avenue.
The child’s identity has not been released, but on Wednesday investigators said the size of the child’s body is consistent with that of an 8-year-old.
“We still don’t have a positive ID,” said San Diego County Sheriff’s Department Lt. Glenn Giannantonio.
Officials are searching for suspect James “Jim” Lee DiMaggio (pictured above, right) in connection with the incident. He owned the home that burned to the ground, and had a “close platonic relationship” with Anderson, according to officials.
Investigators believe DiMaggio abducted Hannah and possibly Ethan. All three may be traveling together in a 2013 Nissan Versa with the license plate 6WCU986.
On Wednesday, officials from the National Center for Missing and Exploited Children said a vehicle resembling the 2013 Nissan Versa was believed to have been spotted in northern California along Highway 395/299 from Alturas northbound, possibly heading toward Oregon or Nevada.
At around 2 p.m., a possible sighting of the suspect vehicle was reported in southern Oregon near Lakeview. Law enforcement officers from multiple agencies across states are on the lookout for the car.
Meanwhile, in San Diego, friends of the missing Anderson children are holding out hope that they’re both still alive.
Outside the family’s apartment in Lakeside, candles burn for Hannah and Ethan.
Neighbors, including Lakeside resident Robyn Nolin, tell NBC 7 they’re shocked.
“How could this happen? What happened? How is this so close to home?” said Nolin.
Three close friends of the Anderson family gathered Wednesday at El Capitan High School, where Hannah is a popular student. The friends said Ethan is also a great kid, beloved by his older friends.
“I mean he had so much ahead of him. It’s crazy,” friend Alan McNabb said.
Hayley Wilcock, a close friend of Hannah’s, said the Anderson siblings really love one another.
"With my brother, we're always fighting, but I've just never seen that with them. They're just always so nice to each other,” said Wilcock, “It was just a really good relationship between them."
Family friend Hannah Darby said they all spent time at the Anderson home, and said Christina Anderson treated them like her own children.
"She was like a second mom to me. She did everything for Hannah and Ethan. And every time they had friends over she would always try to do everything for them as well,” Darby told NBC 7.
"She was just so funny. Always cracking jokes, always smiling; she was a really good mom. She was always nice to her kids. I mean no trouble -- they had the strongest connection I've ever seen," added Wilcock.