SAN FRANCISCO (KRON) -- Residents are permitted to return to their homes after a natural gas leak occurred on Tuesday, according to the San Francisco Fire Department. Due to the leak, four apartment buildings were evacuated after a natural gas leak around 9:45 a.m. Police told KRON4 that a private contractor was working when they struck a natural gas line near 24th Street and Hampshire Street that began to leak.  Red flag warning for Bay Area issued Thursday through Saturday San Francisco Fire Department, the San Francisco Police Department and the San Francisco Municipal Transportation Agency have all responded to the scene. There have not been any reported injuries, according to police.