SAN FRANCISCO (AP) — Hundreds of passengers are being rescreened at San Francisco International Airport's Terminal 3 after a security breach forced the terminal to close.Airport spokesman Mike McCarron tells KGO-TV the terminal was shut down Friday morning after an incident of unauthorized access between 3:30 a.m. and 4 a.m. He declined to provide details, but attributed the incident to a "procedural breakdown."The terminal was shut down and checked. Passengers and employees were rescreened starting around 5:30 a.m.McCarron says some early morning flights could be delayed.The terminal serves United Airlines.