A woman driving an SUV that drifted off Mount Hamilton Road and plunged down a steep slope late Thursday, killing her 52-year-old passenger on his birthday, was arrested on suspicion of vehicular manslaughter while intoxicated, officials said.

The passenger, whose birthday was July 4, was pronounced dead at the scene, according to the California Highway Patrol. His name has not been released.

The driver, Latoya Phillips, 36, of Campbell, told the CHP that the pair had left a restaurant and were headed down Mount Hamilton Road when the 2018 Range Rover Velar went off the road shortly before midnight.

When the CHP responded about 12:15 a.m. Friday, officers and fire crews were able to see the SUV's taillights down the embankment. The crash scene was in the 15600 block of Mount Hamilton Road, about 850 feet east of Alum Rock Road, said CHP Officer Ross Lee.

The SUV landed about 150 feet down and although Phillips was helped up slope, medical crews were unable to revive her front-seat passenger.

The CHP said officers determined that Phillips was under the influence of alcohol and after performing a series of tests, she was arrested on suspicion of felony driving under the influence, and vehicular manslaughter while intoxicated.

Phillips was booked into the Santa Clara County Jail after being medically cleared.

The crash is under investigation.