According to the California Highway Patrol, 38-year-old Albert Silva, of Grass Valley, was driving west on Highway 20. His 2-year-old son was not properly restrained, investigators said.
"It was improperly restrained in the vehicle, the booster seat that the child was using was not for the specified height and weight of that child and so that was what ultimately caused the ejection of the child from the vehicle," CHP Officer Mike Steele said.
At some point, officers say Silva's Ford Focus began to drift. Silva lost control while overcorrecting and the car flipped several times.
"Throughout our investigation, we determined that the male driver was under the influence of alcohol," Steele said.
Silva suffered major injuries but survived, due in large part because he was wearing his own seatbelt, officers told FOX40. His son died at the hospital not long after the crash.
All that remained of the crash scene on Tuesday was parts of a car, some empty cans of beer and some toys.
Silva was released from the hospital Tuesday and immediately booked into the Nevada County Jail. According to the CHP, Silva will face DUI and homicide charges.
"Alcohol intoxication resulting in a death and the circumstances warrant the murder charge at this point," Steele said.
Court records show Silva has a previous DUI conviction in 2013.