Naval Medical Center San Diego Active Shooter Live Updates: Armed Man Spotted At Naval Base

UPDATE: 12:58 p.m. EDT – Investigators were searching the Naval Medical Center in San Diego Thursday after receiving and anonymous report of an armed man at the facility. No person with a gun had been found.

"Investigators have thoroughly searched the building and not found anything yet," spokesman Brian O'Rourke said, the San Diego Union Tribune reported. "They are going floor by floor, it's not a quick operation."