Loved ones gathered to place flowers and candles at Jensen and Trinity Avenues in Kerman.
CHP officers say the Kerman High senior was driving down Jensen when he slammed into the back of a tractor.
The tractor's driver told Action News he had just finished spraying fertilizer and was headed home.
He said he'd already driven several miles when he noticed the car behind him, and never saw any indication the car slowed down.
CHP investigators are looking into other factors that may have contributed to the crash.
Kerman High School says they plan to have counselors on campus for students grieving the loss of their classmate.