The car was traveling on Jackson Street, between Stockton and Grant, about 9:25 p.m. when it was surrounded by about 10 to 15 people. Lt. Mariano Elias said.
A "crowd surrounded and vandalized the vehicle, breaking the window and throwing a firework inside, which set the vehicle on fire," said Sandy Karp, a Waymo spokesperson.
The car was not transporting any passengers and no injuries were reported, Karp said.
"We are working closely with local safety officials to respond to the situation," Karp said.
On Sunday, San Francisco Fire Department issued a social media post that said the use of fireworks is prohibited in San Francisco.
On Monday, Mayor London Breed issued a statement about the Waymo vandalism and fire, calling it a, "dangerous and destructive act of vandalism."
"Chinatown is one of the densest neighborhoods in San Francisco, and any fire could explode and spread among tightly-packed buildings to endanger lives, homes and businesses."
Breed called this an isolated incident and thanked the fire department for their quick response.
Police are investigating the arson and vandalism incident.
You can read the mayor's full response below.
Editor's note: This post was updated to include the mayor's statement.