Authorities have identified the victim of a vehicle crash along Highway 120 east of Escalon on Sunday as 21-year-old Gracie Serna of Stockton.

The accident was reported shortly before 6:30 p.m., the Stockton CHP said, and Serna was a passenger in a 2016 Ram that was westbound on Highway 120, east of Harrold Avenue. According to the CHP report, the driver of the Ram was driving at an estimated 35 to 45 miles per hour, westbound, when the driver observed an unknown black vehicle tailgating them. Unknown to the driver, Serna, who was the middle rear passenger, was leaning her head out the right rear passenger window. The CHP report indicates Serna was ill and had her head outside the vehicle so as not to be sick inside the truck.

The driver moved to the right side of the roadway, partially on the shoulder, to allow the unknown vehicle to pass. As the driver moved to the right, the right side of the vehicle crashed into a wooden post holding a traffic sign for the approaching intersection of Harrold Avenue. The passenger also struck the post and the force of the impact, the CHP report said, caused fatal injuries. Serna was pronounced deceased at the scene. Her identity was released Monday by officials with the San Joaquin County Coroner’s Office.

There were no other injuries reported; the CHP did not indicate how many passengers were in the Ram and had no other information on the black vehicle that passed by the truck as it moved to the right shoulder.