A transgender sex worker found strangled last week near Interstate 280 in Potrero Hill was identified Thursday as a 27-year-old Nicaraguan immigrant. Ruby Ordenana, also known as Ruby Rodriguez, was last seen in the Tenderloin the day before the slaying, said Alexandra Byerly, a project coordinator for EL-LA, a local nonprofit group working with the transgender community. Ordenana was found naked and strangled after 5 a.m. on March 16 at Cesar Chavez and Indiana streets. The medical examiner's office has established her identity and is trying to locate her next of kin. But the local community is holding a vigil...