(FOX NEWS) -- An Idaho woman deliberately drove her sports utility vehicle off a cliff last year, killing herself and her three young children, police said Friday.

The Ada County Coroner’s Office said the deaths in the June 2, 2016, crash were ruled a triple-homicide suicide.

Noel Bankhead, 40, drove a Land Rover off a 50-foot cliff with her daughters and son inside, officials said. The vehicle sank in 40 feet of water in Lucky Peak Lake.

The bodies of Bankhead, Anika Voermans, 13, Logan Voermans, 11, and Gwyneth Voermans, 8, were recovered and the car, with a crushed roof, was pulled from the reservoir.

The cause of death for all four was drowning associated with blunt force trauma.

Witnesses told authorities the car Bankhead was driving suddenly turned slowed down, before it was positioned toward the cliff and accelerated.

Officials said they found nothing mechanically wrong with the vehicle but were unable to recover information from a water-damaged device on the vehicle that records speed, acceleration and braking.

The Ada County Sheriff's Office cited witness statements and lack of skid marks in making its determination that Bankhead acted deliberately. Toxicology tests found no medication or alcohol in Bankhead's system.

Patrick Orr, a spokesperson with the sheriff’s department, declined to comment on Bankhead's motive.

Officials said the mother had gone through a divorce about two years before the crash. She worked full-time as a paralegal and legal secretary for more than 20 years. Her children were described as active and curious with various interests and hobbies.

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