Lynn Jill Nguyen, 21, killed, after her car leaves the State Route 78 roadway in San Marcos, crashes into a tree and overturns.

An Escondido woman who died in a San Marcos freeway crash on Sunday has been identified by authorities as Lynn Jill Nguyen.

The 21-year-old was heading west on state Route 78 about 2:20 a.m. when she lost control of her Acura sedan while changing lanes, the California Highway Patrol said.

Nguyen’s car swerved off the highway near San Marcos Boulevard, struck and tree and rolled. She was dead when paramedics got there, the Medical Examiner’s Office said.