A male skateboarder, who was apparently traveling in the opposite direction of traffic on 20th Street, collided with a car on 20th near Guerrero Street Sunday evening and sustained a head injury. As of Wednesday, he remains in life-threatening condition, according to police.

At around 6:50 p.m. Sunday, the 27-year-old skateboarder was traveling east on 20th toward Valencia Street in the westbound lanes when he  “contacted” the right-front side of a Lexus sedan that was traveling west on 20th, said SFPD spokesman Sgt. Michael Andraychak.

It’s unclear who was at fault. “Investigators are still trying to determine if he had just recently come off the sidewalk or was in the lane for a period of time,” Andraychak wrote in an email.

The driver stayed at the scene following the collision, and “impairment was not considered a factor,” Andraychak said.

Recent calls for service to police can be found on CrimeMapping.

Crime is trauma and the county offers different services, which can be found hereVictims of violent crime can also contact the Trauma Recovery Center at UCSF.