Police Give 'All Clear' at D.C. Navy Yard Following Shooting Reports As Security is Heightened Before Holiday Weekend

A nation is on edge right before the holiday weekend.

The Washington, D.C., Navy Yard was put on full lockdown at 8 a.m. on Thursday. A 911 call reported gunshots fired inside the very same building where a deadly shooting spree took place in 2013.

Read: New York City Prepares for Security Concerns Over July 4 Weekend

In today's incident, there are reports the 911 call may have been an overreaction. No shots were fired and the all-clear was given about two hours later.

The jittery public is preparing to celebrate the 4th of July, just as the FBI and homeland security are advising everyone to be vigilant about a possible terrorist attack.

Long Island Congressman Peter King told Fox News host Megyn Kelly he hasn't seen this level of concern since 911: “This is the real deal. Anyone out there who thinks this is a fake, or just trying to drum up fears, absolutely wrong. You wouldn't see the NYPD doing what it's doing if they didn't have a real concern.”

Read: Tourist Takes Jaw-Dropping Selfie on Brooklyn Bridge

Security is being increased all across the country. At the police command center in Los Angeles, LAPD Captain Jennifer Thomas gave INSIDE EDITION a tour of the command center. The iconic Hollywood sign is just one of the landmarks being watched by hundreds of surveillance cameras.

Cops are also monitoring the internet and social media for any sign of a terrorist threat.

She said: “We're asking everyone to be more vigilant -- if you see something please tell someone."

The celebration is about to begin and everyone is holding their breath.

Watch Below: Are Terrorists Planning to Attack America on July 4?