London Breed maintains lead for San Francisco mayor

The Latest on California's primary election (all times local):
 
10:35 p.m.
 
Business community favorite London Breed is continuing to lead in the race for San Francisco mayor but a winner will likely not be declared Tuesday.
 
The president of the Board of Supervisors had about 36 percent of the vote with about 123,000 ballots counted Tuesday night. 
 
Former state Sen. Mark Leno was in second place with 26 percent of the vote and San Francisco Supervisor Jane Kim had 21.5 percent. 
 
San Francisco could make history by electing its first African-American woman, Breed, for mayor. 
 
San Francisco is an expensive city with a healthy economy thanks to the tech industry, but residents have been grappling with homelessness, filthy streets and traffic gridlock. 
 
San Francisco uses an unusual ranked-choice voting system in which voters select their top-three favorites.