MENDOCINO COUNTY (KPIX 5) -- The search for the three children who are still missing after their family's SUV plunged off a cliff in Mendocino over a week ago intensified Wednesday.
Hannah, Devonte and Sierra Hart haven't been seen in more than a week.
The bodies of their three siblings -- along with their mothers, Jennifer and Sarah Hart -- were all found in or near the wreckage of their SUV. Police think one of the women deliberately drove the vehicle off the 100-foot cliff to their death.
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Wednesday, searchers scoured a six mile stretch of coast between MacKerricher State Park and Noyo Harbor in a coordinated effort.
71 searchers from eight agencies fanned out along the expanse of the Mendocino coastline looking for any sign of the three children still missing after last week's fatal car plunge.
The idea was to use Wednesday's low tides to give rope teams access to rocky areas that were previously unsafe to search due to high surf.
Authorities reported late Wednesday that a cell phone had been found in the area where the SUV landed, but they have not said if the cell phone was connected to any of the passengers in the vehicle.
In the meantime, the California Highway Patrol is conducting something of a parallel investigation in the hopes that those three missing children were not in the car.
Those investigators have been retracing the harts' last steps which produced a photograph of Jennifer Hart buying some groceries at the Safeway in Fort Bragg the day before the family's car was discovered at the bottom of the cliff.
But as for where the family went and what they were doing between that grocery stop and the crash, investigators simply do not know.
On Tuesday, a woman said that she told Oregon child welfare officials in 2013 that Jennifer and Sarah Hart had been depriving the kids of food as punishment.
In a statement provided to The Associated Press, Alexandra Argyropoulos, a former friend of the Harts, said she "witnessed what I felt to be controlling emotional abuse and cruel punishment" toward the six children.
Argyropoulos said she was told after she made the report that Oregon officials had interviewed the children but it was apparent that each child had been coached by their mothers on what to say. She said she was told there was nothing more the Oregon Department of Human Services could do because there was not enough evidence to make a case.
Two weeks ago, Bruce and Dana DeKalb, next-door neighbors of the Harts in Woodland, Washington, called state Child Protective Services because the couple's 15-year-old son Devonte had been coming over to their house almost every day for a week, asking for food.
Dana DeKalb said Devonte told her his parents were "punishing them by withholding food." The boy asked her to leave food in a box by the fence for him, she said.
Devonte, a black boy who is still missing, drew national attention after he was photographed in tears while hugging a white police officer during a 2014 protest.
© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.
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