This is from the City of Oakland "Please note your sidewalk damage may not be caused by an official City street tree, State law and local ordinances hold the owner of fronting property responsible for sidewalk maintenance and repair ( Section 5610 of the Calif State Streets and Highway Code and section 12.04 of the Oakland Municipal Code)."

If the homeowner is responsible, the city will need to let them know and hold them accountable. The sidewalk is impassable for anyone with mobility challenges.