SEA RANCH (CBS SF) — The driver of a vehicle involved in a crash that killed him and two other family members on state Highway 1 in the Sea Ranch area of Sonoma County last month had alcohol in his system, California Highway Patrol officials said Monday.

Jhovani Gonzalez-Marquez, 18, of Gualala, was driving a 1996 Acura Integra too fast through a right curve on northbound state Highway 1 around 4 a.m. on June 29, according to the CHP.

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The Acura crossed double yellow lines, spun counter-clockwise and slid sideways off the west side of the road and into a tree, CHP officials said.

A low tree branch and the vehicle rolling over crushed the interior of the car, according to the CHP.

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Jhovani Gonzalez-Marquez and his brother Aron Gonzalez-Marquez, 14, were pronounced dead at the scene.

The rear seat passenger, Jason Alanis Marquez, a cousin, was taken to Santa Rosa Memorial Hospital by helicopter and was pronounced dead around 7 p.m.

The CHP said it is still investigating whether impairment, speed and fatigue were factors in the crash.

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