Authorities investigating the California cliff plunge that is believed to have killed two adults and their six adoptive children have left open the possibility that three of the children may not have been in the vehicle.

Lt. Shannon Barney, of the Mendocino County Sheriff’s Office, told the New York Daily News on Tuesday that first responders located the bodies of Jennifer and Sarah Hart near the crash site, along with the bodies of Markis, 19, Jeremiah, 14, and Abigail, also 14.

But authorities have been reportedly unable to locate Hannah, 16, Devonte, 15 and Sierra, 12.

“Right now, we have to leave open the possibility they could be in Washington or Oregon or elsewhere in California,” Barney told the paper. “There is always that possibility and we have to leave it open.”

The Daily News report said authorities were working to enhance surveillance video from near the crash site, which could shed new light on the investigation.

Barney told the paper that a massive search was planned for Wednesday that will take place during low tide.

Information pulled from the vehicle's software shows it was stopped at a flat, dirt pull-off area before it sped off the steep rocky face and plunged 100 feet, said Capt. Greg Baarts with the California Highway Patrol Northern Division.

Baarts said Monday that the electronic information, combined with the lack of skid marks or signs the driver braked, led authorities to believe the crash was purposeful.

Known as the Hart Tribe, the multiracial family of two married women — Sarah and Jennifer Hart — and six adopted children often took spontaneous road trips to camp and hike and traveled to festivals and other events, offering hugs and promoting unity.

Authorities don't know exactly when the wreck took place. A passing motorist discovered the vehicle March 26, three days after social service authorities in Washington state opened an investigation apparently prompted by a neighbor's complaint that the children were being deprived of food. Authorities believe at least one felony was committed but Van Patten declined to specify.

"To the best of my knowledge, there was not a suicide note found at the residence," said Baarts, who added that authorities have been interviewing friends and family members of the Harts.

The Associated Press contributed to this report.