On March 26, 2018, Jennifer Jean Hart (38) drove the family's GMC Yukon XL off a roughly 100-foot cliff on California State Route 1 near Westport, in Mendocino County, California. Jennifer was in the driver's seat and her wife, Sarah Margaret Hart (38), was in the front passenger seat. All six of the couple's adopted children — Markis (19), Hannah (16), Devonte (15), Abigail (14), Jeremiah (14), and Ciera (12) — were also in the vehicle. Five of the children's bodies (Hannah, Markis, Jeremiah, Abigail, and Ciera) were found in or near the wrecked SUV, which landed upside down on a beach below the cliff. Devonte's body has not been recovered; a superior court judge ruled in 2019 that he had been in the vehicle at the time of the crash, and a death certificate was issued that year.
Jennifer and Sarah Hart were both originally from South Dakota and met at Northern State University, later marrying in Connecticut in 2009. They adopted three children from Colorado County, Texas, in 2006 and three more from Houston in 2008; all six children had Black African ancestry. The family lived in Minnesota, Oregon, and later Washington state prior to the deaths.
The family had a documented history of abuse allegations across multiple states. In Minnesota in 2008, a teacher noticed bruises on one child and was told she had been struck with a belt; Sarah later pleaded guilty to assault and received community service. In 2013, Oregon authorities investigated abuse allegations after reports that the children were underfed and controlled, though interviews with the children at that time did not surface new incidents and the investigation reached no conclusion. In August 2017, after the family moved to the Woodland, Washington area, one of the daughters, Hannah, jumped from a second-story window and sought help from neighbors, alleging abuse. Neighbors also reported that another child, Devonte, had described being denied food. The neighbors reported the family to police and to Washington's Department of Social and Health Services, which attempted unsuccessfully to contact the Harts on March 23, 2018, and again on the day of the crash.
Expert analysis of the SUV's onboard computer indicated the vehicle had been intentionally accelerated from a stop to 20 mph within three seconds with full throttle before going over the cliff edge. A fourteen-member coroner's jury unanimously ruled the deaths a murder–suicide. The California Highway Patrol stated no criminal prosecution was possible because all potentially responsible parties were deceased. Toxicology showed Jennifer's blood alcohol content exceeded the legal limit, and diphenhydramine was found in Sarah's system and in two of the children. Sarah had made internet searches before the crash regarding the lethality of Benadryl and death by drowning. The Mendocino County Sheriff's Department closed the case and released declassified records in 2019.