An employee working at the celeb-favorite Nobu restaurant in Malibu is dead after cops say a teen driver struck his parked car while he was inside.

Ryo Uchimiya had arrived early to work on Sunday ... and while he was waiting within his vehicle on the Pacific Coast Highway, a Range Rover plowed into his car ... according to the Los Angeles Times.

The Range Rover -- police say -- was driven by a 16-year-old who was apparently speeding.

A witness told KTLA that the driver seemed stunned after the crash.

She said ... "I heard throughout the day that maybe he didn’t even have a license. He’s a young kid. He looked very young and very confused and his parents didn’t even show up to find him. He was sitting there for two hours by himself."

Authorities say an investigation is ongoing ... and that no charges have been filed.

According to the L.A. Medical Examiner's Officer ... an exam on Uchimiya's body has been scheduled.

Uchimiya was only 51.

RIP