The cars are all moving slowly, at least relative to the Tesla, which is seen speeding up Taylor, through a red light.
It takes one second for the Tesla to broadside a Mini Cooper, which had the green light, and then hit a couple who were in the crosswalk.
In the video, you can see that Kelly Dean saw the Tesla coming, stopped, and threw her arm across her husband, before the Tesla hit them both, throwing them into the air.
VIDEO: Woman arrested in connection with deadly SF crash
"She was incoherent, gurgling noises, she was on her stomach with her head off to one side," said Bob Navarro, who ran to help the couple and stayed with Kelly, who was unresponsive. "I could see a lot of blood coming from her head and we just kept talking to her, talking to her."
Kelly survived and, as of Monday night, is at San Francisco General Hospital in critical condition.
But her husband, 39-year-old Benjamin Dean, died.
The couple, from the Fresno area, were in San Francisco celebrating their wedding anniversary.
The driver of the rented Tesla, 21-year-old Kelsey Cambridge of Vallejo, was arrested Sunday and booked for involuntary vehicular manslaughter.
VIDEO: Vallejo woman identified as Tesla driver in San Francisco crash that killed tourist from Central Valley
"Pedestrian fatalities are way up this year, and most of those are here in this neighborhood," said San Francisco Supervisor Matt Haney.
Sunday's deadly wreck happened in the Tenderloin - the heart of Haney's district, and the city's "high injury network." The dangerous areas are mostly concentrated in the downtown, SOMA and Tenderloin neighborhoods.
"We are in a crisis, we are in a state of emergency and it's time that the city recognize that," said Haney.
"Speed is the number one killer," said Jodie Medeiros, the executive director of Walk San Francisco, a pedestrian advocacy organization. She wants new policy that slows down drivers. "Street design changes and re-engineering to really impact how people are driving in our city."
Supervisory Haney will be joining Medeiros for a rally Tuesday at 9 a.m. at San Francisco City Hall, to urge city leaders to declare a state of emergency for pedestrian safety to better facilitate quick action. Haney says he's interested in narrowing streets, eliminating lanes and installing speed and red light cameras to improve traffic conditions in his district.