A 69-year-old woman was struck and killed by the driver of a pickup truck at 19th and South Van Ness around 3:26 p.m. Thursday, according to police.

How the incident transpired is under investigation, police say. But San Francisco Police Department spokesman Officer Robert Rueca said that shortly following the collision, officers responded to the incident and discovered the woman suffering from life-threatening injuries. She was transported to the hospital, where she subsequently died.

“The driver and the vehicle remained on scene and cooperated with our investigation,” Rueca said. “No arrest was made, nor is an arrest pending.”

The woman is the 16th pedestrian or cyclist to be killed in a vehicle collision this year, according to Walk San Francisco, a pedestrian advocacy organization.

“Our hearts go out to the victim’s family and friends,” Jodie Medeiros, executive director of Walk San Francisco, said in a statement. “We have a crisis on our streets with traffic safety. Lives are being lost all too frequently, and devastating families and our communities.”

South Van Ness is notorious for fast-moving vehicles. It is on the city’s “high-injury network,” the 13 percent of streets where 75 percent of traffic collisions occur.