A man who crawled beneath a delivery truck parked in a SoMa alley suffered life-threatening injuries Tuesday afternoon, when the truck's driver started the vehicle and ran him over.

The San Francisco Police Department was called to the 400 block of Jessie Street, an alley which runs through Mint Plaza, at 2:14 p.m. Tuesday.

When they arrived, witnesses told them that a 28-year-old man had apparently crawled beneath a parked delivery truck.

"When the driver returned, unaware [the victim] was under his vehicle, he started to drive away" and ran the victim over in the process.

Police say that the man beneath the truck suffered life-threatening injuries as a result of the incident. He was transported to San Francisco General Hospital for treatment.

The driver, police say, "stayed at the scene and cooperated with investigation." Further details on the case, including why the man crawled beneath the truck in the first place, were not available at publication time.