The search is on for 71-year-old Gwyneth Borden, an at-risk individual with Alzheimer’s who has gone missing in San Francisco. According to the San Francisco Police Department, Borden was last seen on Saturday, February 17, at about 10 a.m. when she left her home on the 3800 block of Mission Street. Authorities are urging the public to step forward with any information that could help to locate her safely.