A man who was riding between two segments of a fuel tanker as it drove through the Tenderloin Tuesday night was run over by the truck after he lost his grasp and fell beneath its wheels. Today, police are seeking the driver of the truck, saying that it's unlikely that he or she is aware that they ran over this man.

According to San Francisco Police Department spokesperson officer Gordon Shyy, a 35-year-old man "for unknown reason was hanging onto a double gas tanker truck, in the space between the two gas tanks" at 11:50 Tuesday night.

As the tanker's driver turned from Mason to Turk Streets, Shyy says, the man "fell and was struck by the gas tanker."

He was pronounced dead at the scene, found, KRON4 reports, "in the middle of the street with a San Francisco Giants cap lying next to him."

According to Shyy, the strange circumstances of the incident were "gathered from independent witnesses," but no one is sure why the man, who has yet to be publicly identified by the San Francisco Medical Examiner, was riding between the tanks, or what caused him to fall.

Shyy says that due to the odd circumstances of this collision, the driver probably doesn't know the role they inadvertently played in this man's death. According to the Chron, the truck "had two silver tanks and a dark cab," and "may have offloaded fuel at a rental car company on O’Farrell Street shortly before the crash."

Investigators are working to locate the tanker, Shyy says, and are seeking area surveillance tape and other witnesses to the incident. Anyone with information is asked to call SFPD's anonymous tip line at (415) 575-4444 or text a tip to “SFPD” at TIP411.