Reports of an active shooter at Naval Medical Center San Diego (NMCSD) Tuesday morning led to a lengthy lockdown of the military facility, but U.S. Navy officials confirmed no gunman was found and no injuries were reported.

NMCSD was placed on lockdown just after 8 a.m. and people inside were ordered to shelter in place after an unidentifed Department of Defense employee reported hearing three shots fired in the basement of Building 26, which houses a gym and barracks, according to the Navy.

More than two hours later, K9 units were sweeping the military medical center, honing in on Building 26, Brian O'Rourke, PAO Navy Region Southwest said.

Initial searches of Building 26 turned up no evidence of a gunman or shots fired, O'Rourke said.

When Naval Medical Center San Diego went into lockdown, some San Diegans were not able to access loved ones in the hospital. NBC 7’s Military Reporter Bridget Naso has that side of the story.

N. Scott Sutherland, Deputy Director of Public Affairs for Navy Region Southwest, sent out the following information just after 10:30 a.m., echoing the details from O’Rourke.

“The investigation of Building 26 continues. First responders and Navy working dog units have conducted an initial top down inspection of the Building and have not located any casualties or evidence of a shooting having taken place. There have been no reported casualties at this time. There is a secondary, more thorough floor by floor inspection taking place at this time. The medical facility remains on lockdown and a shelter in place order remains in effect.”

“Patients needing immediate medical attention should go to their nearest Naval Medical facility other than Balboa Park,” Navy officials added.

After a lengthy lockdown and massive law enforcement response, Naval Medical Center San Diego (NMCSD) was deemed safe and cleared of the reported threat of an active shooter. No evidence of a shooting was found. NBC 7’s Greg Bledsoe reports.

The first alert of a possible active shooter at the facility came around 8:10 a.m., after NMCSD posted the following notice to its Facebook page:

“**!ATTENTION!** An active shooter has just been been reported in building #26 at Naval Medical Center San Diego. 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.” [[366563381,C]]

NMCSD employees received the following text message alert:

"CODE WHITE NMCSD. SHELTER IN PLACE AND STAND CLEAR OF BUILDING 26 POSSIBLE ACTIVE SHOOTER IN BUILDING."

But Navy officials said at 10:30 a.m. that there was no threat at the Naval hospital.



“We have done a number of clearing sweeps of the building and as of this time, we have found nothing that substantiates those reports,” explained Capt. Curt Jones, Commanding Officer of Naval Base San Diego.



“We are continuing to clear the building to ensure there are no casualties and there’s nothing that’s not quite right in the building,” he continued. “I can tell you the person who reported the gunshots was in the building at the time and reported that they thought they heard three gunshots.”

NMCSD Capt. Curt Jones speaks to reporters during as press conference, discussing the reported threat at the center.

“As of now we have found absolutely nothing that indicates there were any shots fired. There are no casualties at this time,” Capt. Jones added. “I’d like to emphasize, we take all reports like this very seriously. We do a lot of training to help people recognize what they’re supposed to do in the event of an active shooter.”

Capt. Jones said many San Diego-based agencies aided in the emergency response. Officials with some agencies came on their own when they heard something extremely serious may have been happening at the facility.



Building 26 at NMCSD serves a number of functions: barracks, a gymnasium, facilities for wounded warriors, medical administration, and residential and office facilities, Jones said.



Capt. Jones said part of prior training at the facility has included telling active duty and civil servants to do three things in case of an active shooter situation: “run, hide or fight,” just as NMCSD’s initial Facebook alert advised.

As the situation unfolded just after 8 a.m. and a massive law enforcement response stormed the facility, NMCSD advised all personnel to not report to work and avoid the area.

At that point, NMCSD officials told NBC 7 that, as far as they knew, this was not an active shooter drill or training.

At around 9:15 a.m., NMCSD released the following details, which were still developing:

"The sound of gunshots were reported in the basement of building #26 at Naval Medical Center San Diego at about 8 a.m. today. Naval Medical Center San Diego is treating this as a possible active shooter. All personnel are advised to execute active shooter procedures. Non-emergency response personnel are asked to stay away from the compound. San Diego Police Department and Chula Vista S.W.A.T. are on scene at building #26."

One by one, individual buildings at the Naval hospital were all placed on lockdown, one employee told NBC 7. The front gate to the facility was also locked.

Florida Drive was blocked off to traffic as law enforcement surrounded the area, including California Highway Patrol officers who were seen entering the facility through an emergency room entrance. A steady stream of patrol cars from multiple agencies, including the San Diego Police Department (SDPD) and Chula Vista Police Department (CVPD), could then be seen flowing into the area.

With access to some roads blocked, traffic was backed up for miles.

By 8:45 a.m., a SWAT truck honed in on the military hospital.

Images: Active Shooter Reported at NMCSD

A concerned staffer for the childcare center at NMCSD told NBC 7 that employees at the facility have undergone training in the case of an active shooter situation. The staffer said the childcare center opens daily at 5:30 a.m., so, at the time of the reported incident, there could have been more than 200 children there.

“This is the first time I’ve ever seen this happen," the staffer told NBC 7. "I’m thinking this is something real serious if the SWAT team has to come in. It’s really concerning for me that there’s something going on at the hospital.”

At 9:08 a.m., Naval Base San Diego officials posted this update on Twitter for parents of kids at the childcare facility: "For all concerned, the childcare facilities at NMC are currently secured. All children are accounted for and safe."

NBC 7 also spoke with military couple, Nikki and Broderick, whose son, Sydney, is a patient at the Neonatal Intensive Care Unit (NICU) inside the military hospital.

The couple waited anxiously outside NMCSD gate Tuesday morning, waiting for any information on the activity, hoping to soon be reunited with their baby boy, who was born at 34 weeks gestation.

They both said they understood the extra precautions preventing them from getting to their son.



“I want them to have this situation under control as much as possible because I wouldn’t want anything to happen to anyone,” Broderick said.

Missing Attachment Emergency workers from around San Diego arrived quickly at the medical center in the center of Balboa Park on Tuesday morning after reports were received of an active shooter.

Navy Petty Officer King, an X-Ray instructor at the medical center, was waiting outside like everyone else. Some of his students had reached out to him to check on his safety.



“I just hope no one is hurt today,” King said while he waited for word on what was going on inside the facility.



NBC 7 spoke with a source whose mother was locked down inside the Occupational Room on the second floor of Building 26. She said her mother sent her a text message saying everyone was safe. They were told to barricade the door, stay quiet and shelter in place.

NBC 7 also spoke with representatives inside the facility's Continuous Improvement Department, at Building 6-5, and at Building 1-3, the facility's Dialysis Center, who said everyone inside those buildings was safe. They were all told to shelter in place and remain on lockdown..

By 10:05 a.m., officials were seen leading people out of the facility with their hands up. A law enforcement official told NBC News’ Pete Williams an initial sweep of the building turned up no forensic evidence of shots fired. They were checking rooms a second time and working to locate the person who made the original report.

!UPDATE/REMINDER!



Investigation still ongoing at NMCSD. All personnel continue to remain clear of NMCSD and... https://t.co/aQTiroVYgS — NBSD (@NavBaseSD) January 26, 2016

Meanwhile, amid the investigation at NMCSD, several temporary lockdowns were activated, including one at Naval Base Point Loma. By 9:35 a.m., that lockdown had been lifted, officials confirmed.

San Diego Unified School District (SDUSD) officials confirmed the following nearby schools had also been placed on temporary lockdown: Garfield Middle School on Oregon Street, San Diego High School on Park Boulevard and Roosevelt Middle School, also on Park Boulevard.

SDUSD officials said the lockdowns were precautionary, and that all staffers and students across the campuses were safe. By 9:45 a.m., the SDUSD confirmed those school lockdowns had been lifted.

At a second news conference at noon, both San Diego Mayor Kevin Faulconer and SDPD Chief Shelley Zimmerman praised the quick response and teamwork by local and federal agencies.

“This is what we train for, as a region, as a city,” said Faulconer.

“This is exactly what we want and we train for this. When that call came in that there was an active shooter on the base, no one hesitated,” added Zimmerman, calling the coming together of law enforcement a “unified collaborative response.”

At that briefing, Capt. Jones said investigators remained at the Naval hospital and were still working to clear Building 26 “in a very methodical fashion.”

He said that within the initial report of gunfire at the building, about 10 minutes passed before the entire NMCSD staff had received the warning and the wheels were in motion for city, county, state and federal law enforcement agencies to begin working together.

“There is a very substantial response that would ensure that if there was a problem, it would have been immediately dealt with,” he added.

By 2 p.m., Navy officials released another update, saying the shelter in place order had been lifted for all parts of the facility, with the exception of Building 26, and personnel were permitted to move about.

Access to NMCSD was resuming, as well as patient care, officials said. The main and emergency gates to the facility were reopened to outbound traffic.

By 3:40 p.m., the shelter in place order was lifted for Building 26 as well.

"Operations are going back to their normal cycles at the hospital as patient care and access to the NMCSD facility is resuming to business as usual," Navy officials said.

According to the NMCSD’s website, Building 26 -- the site at the center of Tuesday's incident -- houses several amenities, including a fitness center. The Liberty Center is also located near Building 26, and offers recreational activities for all active duty service members and NMCSD ID cardholders, including a cyber café, billiards tables, a music room and a 25-seat movie theater.

The large staff at NMCSD is comprised of more than 6,500 military, civilian, contractor and volunteer personnel. The 272-bed, multispecialty hospital and ambulatory complex is located on 78.4 acres in the southeast corner of Balboa Park, about 2.5 miles from downtown San Diego.

The military hospital treats families of military members, too.

NMCSD personnel deploy to Iraq, Afghanistan, Kuwait, Djibouti and aboard the USNS Mercy. The facility is affiliated with 19 civilian nursing schools, training more than 400 students per year in clinical rotations.