A 15-year-old boy featured in a widely shared photo of him hugging a Portland police officer in 2014 is one of two children still missing after an SUV with their family inside plunged off a Northern California cliff.

Devonte Hart and his sister Hannah, 16, have yet to be found since the wreckage was discovered March 26 by a passer-by off Route 1 near Westport, California. The crash killed Jennifer Hart and Sarah Hart, both 38, and their children, Markis Hart, 19; Abigail Hart, 14; Jeremiah Hart, 14; and Sierra Hart, 12. Sierra Hart's legal name is "Ciera."

Here's a timeline of what we know so far:

March 2004: Earliest known public record that shows Jennifer Hart and Sarah Gengler, both from South Dakota, residing in Alexandria, Minnesota.

April 2005: The couple is licensed to provide child foster care in Douglas County, Minnesota, for almost two years beginning April 1, 2005.

May 2005: Sarah Hart petitions to change her last name from Gengler to Hart.

August 2006: A Harris County District Court (Texas) judge orders the parental rights of the biological parents of Devonte, Jeremiah, Sierra and a fourth child terminated.

September 2006: Jennifer and Sarah Hart adopt siblings Markis, Abigail and Hannah.

December 2006: The Texas Department of Family and Protective Services removes Devonte, Jeremiah, Sierra and a fourth child from the care of an aunt, Priscilla Celestine, after a caseworker visit. The children are then placed in foster care.

May 2007: The aunt, Celestine, files a petition to adopt all four children while they are being cared for by the state of Texas. The petition is denied in Harris County District Court the next year. The aunt files a motion for a new trial, and that is denied as well.

September 2008: According to a police report from Alexandria, Minnesota, Hannah, then 6, tells authorities that one of her mothers bruised her with a belt. Asked about the beating, Jennifer and Sarah Hart tell a police investigator and social worker the girl had fallen down the stairs.

October 2008: Celestine appeals to a Texas appeals court to overturn the adoption petition and new trial dismissals.

February 2009: Jennifer and Sarah adopt Devonte and two of his siblings — bringing their number of children to six. An article from Paper Trail, a New Zealand-based news outlet, describes his adoption. The article said by age 4, the boy had been abused, neglected, shot at and had endured other traumas. The fourth child, Dontay Davis, is not adopted by the Harts.

July 2010: A Texas appeals court turns down Celestine's attempt to adopt Devonte Hart and three of his siblings, court records show.

November 2010: Police in Alexandria, Minnesota interview Abigail Hart, 6 at the time, after a teacher discovers bruises stretching from her sternum to her navel. The girl says Jennifer Hart hit her with a closed fist, put her head in a cold bath, then hit her again, court records show. She was then grounded, the girl told police, which meant she had to stay in bed and miss lunch.

April 2011: Sarah Hart pleads guilty to abusing Abigail Hart and is sentenced to a year of probation for misdemeanor domestic assault, court records show. Sarah told police she was the one who hit Abigail, even though the girl told authorities her mother Jennifer had done it. The next day, all six of the Hart children are taken out of public schools. They never attend public school again.

October 2011: The family lives in Alexandria, Minnesota, for a time and takes part in local activism. Hart family members including Devonte and Jennifer Hart participate in an Occupy Minneapolis demonstration.

2012: According to friends in Oregon, Sarah Hart travels to Portland to look for work. Jennifer Hart and their children later join her.

2013: After the family moves to West Linn, family friend Alexandra Argyropoulos tells Oregon child welfare officials that the Hart parents have been depriving their kids of food as punishment, she says. The Harts break off contact with her when they learn of it. Argyropoulos says she was told the Hart children had been interviewed by Oregon officials; it was apparent that each child had been coached by their mothers on what to say; and nothing more could be done by the Oregon Department of Human Services.

July 2013: The police department responds to a call to the Hart's house.

November 2014: Family members participate in a Portland protest of a Missouri grand jury declining to indict a Ferguson police officer in the fatal shooting of Michael Brown. Devonte and a Portland police officer hug, and the photo of the moment goes viral.

March 2016: Family members join U.S. Sen. Bernie Sanders of Vermont onstage during a presidential campaign rally in Vancouver.

May 2017: Jennifer and Sarah Hart buy a two-story, 3-bedroom home on 2 acres of land in the Woodland area of Clark County, Washington, property records show.

November 2017: Steve Frkovich, a relative of the Harts' neighbors, tells a dispatcher that he is concerned about the children. He says he feels the kids are "being highly abused" and recounts Hannah Hart jumping out a window and seeking help. The incident happened a few months prior to his call to authorities, and a neighbor — Frkovich's daughter — says there have been no other issues since that one.

March 23, 2018: The Washington State Department of Social and Health Services opens a Child Protective Services investigation in which the Hart children are "identified as potential victims of alleged abuse or neglect."

March 23, 2018: The Washington State Department of Social and Health Services attempts without success to make contact with the Hart family.

March 24, 2018: Sarah Hart sends a 3 a.m. text message to a friend, saying she's so sick she might have to go to the hospital. The friend, Cheryl Hart, never hears from Sarah again.

March 24, 2018: The family is in or around Newport, Oregon, around 8:14 a.m., police say. It's believed they continue south on Route 101 until they reach State Route 1 in Leggett, California.

March 24, 2018: The Harts travel south on State Route 1 until they reach the Fort Bragg area in Mendocino around 8 p.m.. The family stays there until about 9 p.m. March 25, 2018.

March 26, 2018: Cheryl Hart calls a Clark County emergency dispatcher at at 1:15 p.m., asking the Clark County Sheriff's Office to do a welfare check at the family's Woodland, Washington, home.

March 26, 2018: The Washington State Department of Social and Health Services again unsuccessfully attempts to make contact with the Hart family.

March 26, 2018: A passer-by along Highway 1 in Westport, California, calls 911 after looking down a 100-foot embankment and seeing an SUV upside down on the rocky shoreline. Five people are found dead: three children outside the SUV and two women inside.

March 27, 2018: The Washington State Department of Social and Health Services makes a third unsuccessful attempt to contact the Hart family.

March 28, 2018: The women are identified by the Mendocino County's Sheriff's Office as Jennifer and Sarah Hart and their children as Markis, Jeremiah and Abigail. Three of their other children: Devonte, Hannah and Sierra, remain missing. Sheriff Tom Allman said a search is ongoing for the remaining three children.

March 29, 2018: Police continue to search for the three missing children, including Devonte, and to investigate why the SUV plunged off the California cliff. Authorities don't know if the kids were also in the car, but are basing their search on the assumption that they were thrown from the car into the cliffs or the surf.

March 31, 2018: Officials reveal the speedometer on the Harts' wrecked SUV was "pinned" at 90 mph.

April 2, 2018: Officials say the crash may have been intentional, saying data taken from the family's SUV shows the vehicle came to a complete stop at the Route 1 pullout before speeding off the cliff. The search for the missing children becomes a "recovery effort."

April 2, 2018: "I'm to the point where I'm no longer calling this an accident, I'm calling it a crime," Mendocino County Sheriff Tom Allman tells HLN's Ashleigh Banfield.

April 7, 2018: An unidentified body, believed to be that of a black female, is found in the ocean near the site of the crash. Officials say an identification could take weeks.

April 13, 2018: California Highway Patrol officials tell reporters Jennifer Hart had a blood alcohol level of .102 when she drove the SUV off the cliff the previous month. Capt. Bruce Carpenter also told reporters toxicology reports indicated Sarah Hart had "a significant amount of the ingredient primarily in Benadryl in her system." Two of the three children also had "Benadryl-type of substances in their system."

April 17, 2018: Authorities announce that the body found in the Pacific Ocean surf near the crash site April 7 belongs to Sierra Hart, 12. Her legal name is "Ciera."

Two of her siblings, Devonte and Hannah Hart, remain missing. They are presumed dead. The FBI has posted missing person fliers for both children on its website.

— The Oregonian/OregonLive