An active shooter was reported Tuesday morning at the Naval Medical Center San Diego, triggering a massive response from law enforcement, but the incident appears to have been a false alarm.
Capt. Kurt Jones, commander of U.S. Naval Base San Diego, said an investigation into the matter turned up "absolutely nothing."
"As you're aware, we've had reports -- I'd like to emphasize the word 'reports' -- of shots fired this morning," he said during a press conference later in the day. "As of right now we have found absolutely nothing that would indicate that any shots were fired."
His comments came a few hours after the medical center announced on its Facebook page a report of an active shooter on campus. The message began, "ATTENTION!" and advised employees and patients to "run, hide or fight."
"An active shooter has just been been reported in building #26 at Naval Medical Center San Diego," it states. "All occupants are advised to run, hide or fight. All non-emergency response personnel are asked to stay away from the compound, located at 34800 Bob Wilson Drive, San Diego, CA 92134."
The Navy in a statement later confirmed "a single witness" reported shots fired at the location.
"According to initial reports of a single witness, at approximately 8 a.m. this morning three shots were reportedly heard in the basement of Building 26, a combination gym/barracks, at the Navy's Medical Center Balboa Park facility," it stated. "First responders and Navy working dog units are on scene clearing Building 26. The Medical Center is on lockdown and a shelter in place order has been given."
There were no reports of any injuries and no patients were evacuated during the incident, according to Capt. Jose Acosta, commanding officer of the San Diego Naval Medical Center.
NBC later reported that a Navy source said an "initial sweep of building 26 found no signs that shots were fired" and officials couldn't find the person who made the call.
Live television footage showed police cars and SWAT trucks, including a K-9 unit, responding to the scene. Officials from the U.S. Marshals, Justice Department, California Highway Patrol and other law enforcement departments were also reported on the scene.
CNN reported the Naval Medical Center San Diego, including its child care facility, was secure. The center admits some 19,000 patients a year with a variety of medical services, including births, according to the news organization. The facility also houses offices and barracks for wounded sailors and Marines.
The nearby Naval Base Point Loma was temporarily locked down, as were nearby schools.
"We're not taking any chances and are executing procedures we've been trained for in this kind of situation," spokesman Mike Alvarez told the Associated Press.
Deadly shootings have occurred in recent years at military installations in the U.S., including Fort Hood, Texas; the Washington Navy Yard in Washington, D.C.; and facilities in Chattanooga, Tennessee.