Thousands of people from across the Bay Area trekked through the rain Friday to the Oakland Coliseum for free health care. The services were offered by about 600 volunteer doctors, dentists and others, 98 percent of whom are members of the Seventh-Day Adventist Church. The group also offered clinics at the Armory in San Francisco’s Mission District on Wednesday and Thursday, but organizers said Friday’s event was by far the busiest. Pacifica’s Geoffrey Upton was there and files this report.