Homicide

Investigators pore over Idaho wreck that killed mom, 3 kids

  • In this photo provided by the Ada County Sheriff's Office, Ada County Sheriff's Deputies and divers with the Boise Fire Department stand by the wreckage of an SUV driven by a 40-year-old Boise woman that plunged off a cliff into the Lucky Peak Reservoir Thursday, June 2, 2016, in Boise, Idaho. Divers with the Boise Fire Department recovered the bodies of two girls, ages 12 and 6, and the body of a 10-year-old boy from the vehicle, which was about 40 feet below the surface Thursday morning, according to the Ada County Sheriff's Office. A witness saw the SUV accelerate from the side of the road to go over the cliff, the sheriff's office said. (Patrick Orr/Ada County Sheriff's Office via AP)

    In this photo provided by the Ada County Sheriff's Office, Ada County Sheriff's Deputies and divers with the Boise Fire Department stand by the wreckage of an SUV driven by a 40-year-old Boise woman that plunged off a cliff into the Lucky Peak Reservoir Thursday, June 2, 2016, in Boise, Idaho. Divers with the Boise Fire Department recovered the bodies of two girls, ages 12 and 6, and the body of a 10-year-old boy from the vehicle, which was about 40 feet below the surface Thursday morning, according to the Ada County Sheriff's Office. A witness saw the SUV accelerate from the side of the road to go over the cliff, the sheriff's office said. (Patrick Orr/Ada County Sheriff's Office via AP)  (The Associated Press)

  • In this photo provided by the Ada County Sheriff's Office, Ada County Sheriff's Deputies and the Boise Fire Department dive team stand by the wreckage of an SUV driven by a 40-year-old Boise woman that plunged off a cliff into the Lucky Peak Reservoir Thursday, June 2, 2016, in Boise, Idaho. Divers with the Boise Fire Department recovered the bodies of two girls, ages 12 and 6, and the body of a 10-year-old boy from the vehicle, which was about 40 feet below the surface Thursday morning, according to the Ada County Sheriff's Office. A witness saw the SUV accelerate from the side of the road to go over the cliff, the sheriff's office said. (Patrick Orr/Ada County Sheriff's Office via AP)

    In this photo provided by the Ada County Sheriff's Office, Ada County Sheriff's Deputies and the Boise Fire Department dive team stand by the wreckage of an SUV driven by a 40-year-old Boise woman that plunged off a cliff into the Lucky Peak Reservoir Thursday, June 2, 2016, in Boise, Idaho. Divers with the Boise Fire Department recovered the bodies of two girls, ages 12 and 6, and the body of a 10-year-old boy from the vehicle, which was about 40 feet below the surface Thursday morning, according to the Ada County Sheriff's Office. A witness saw the SUV accelerate from the side of the road to go over the cliff, the sheriff's office said. (Patrick Orr/Ada County Sheriff's Office via AP)  (The Associated Press)

  • In this photo provided by the Ada County Sheriff's Office, the Boise Fire Department dive team searches for an SUV driven by a 40-year-old Boise woman that plunged off a cliff into the Lucky Peak Reservoir Thursday, June 2, 2016, in Boise, Idaho. Divers with the Boise Fire Department recovered the bodies of two girls, ages 12 and 6, and the body of a 10-year-old boy from the vehicle, which was about 40 feet below the surface Thursday morning, according to the Ada County Sheriff's Office. A witness saw the SUV accelerate from the side of the road to go over the cliff, the sheriff's office said. (Patrick Orr/Ada County Sheriff's Office via AP)

    In this photo provided by the Ada County Sheriff's Office, the Boise Fire Department dive team searches for an SUV driven by a 40-year-old Boise woman that plunged off a cliff into the Lucky Peak Reservoir Thursday, June 2, 2016, in Boise, Idaho. Divers with the Boise Fire Department recovered the bodies of two girls, ages 12 and 6, and the body of a 10-year-old boy from the vehicle, which was about 40 feet below the surface Thursday morning, according to the Ada County Sheriff's Office. A witness saw the SUV accelerate from the side of the road to go over the cliff, the sheriff's office said. (Patrick Orr/Ada County Sheriff's Office via AP)  (The Associated Press)

Authorities in Idaho are trying to determine what caused an SUV to go off a steep cliff and into a reservoir, killing a woman and her three children.

Investigators say they'll study the wreckage to determine if the vehicle had any mechanical problems.

The Ada County Sheriff's Office says an autopsy also will be done Friday on the body of the mother, a 40-year-old from Boise.

The crash also killed her 6-year-old and 12-year-old daughters and her 10-year-old son. The Ada County Coroner's Office is expected to release their names in the next few days.

The SUV plunged about 70 feet off a cliff and into Lucky Peak Reservoir on Thursday.

Sheriff's officials say a witness saw the vehicle first accelerate from the side of the road. Deputies say they found no skid or brake marks where the vehicle went over the edge.