Washington(CNN) President Donald Trump was briefly taken to a White House bunker on Friday night as protesters demonstrated across the street, and while the annex of bunkers and tunnels under the White House are nothing new, they're rarely used by American presidents.
A bunker was originally constructed under the East Wing during Franklin D. Roosevelt's presidency in the wake of the Pearl Harbor attack and more recently the Presidential Emergency Operations Center was used during the 9/11 attacks.
According to a White House official and a law enforcement source, Trump was briefly taken to the underground bunker as protesters gathered outside the White House in the wake of George Floyd's death that sparked a series of demonstrations across the country. Trump sought to explain his presence as an "inspection," rather than a retreat for his own safety.
The President was there for a little under an hour.
A law enforcement source and another source familiar with the matter tell CNN that first lady Melania Trump and their son, Barron, were also taken to the bunker.
Roosevelt was first spurred to construct a shelter underground on the heels of the 1941 Pearl Harbor attack. He began with a subterranean expansion project to build what was more akin to an air raid shelter than a bunker. There were two different projects -- one directly under the White House and a second with a ramp (Roosevelt used a wheelchair) down to the Treasury Department vaults, according to CNN contributor Garrett Graff's book, Raven Rock.
"A White House bunker was an absolute necessity during World War II," CNN Presidential Historian Douglas Brinkley said in an interview. "We were terrified that Germany was going to try to blow up Washington, DC. ... The Germans were building rockets," Brinkley said. "It was a bullseye, the White House."
Eventually, White House security determined that even the bunker wasn't safe enough, which is when Roosevelt began traveling to the hidden retreat in the mountains of Maryland which he named "Shangri-La" -- what is now known as Camp David. At the time, nobody knew its location.
"Nobody knew FDR wasn't in the White House. People were assuming he was operating out of the bunker when he was often in the Maryland woods," Brinkley said. "There was a dual defense between having the bunker in the White House and having Camp David."
Harry Truman's White House began the massive work to turn the bunker into a bomb shelter the day before American boots hit the ground in South Korea. Truman's naval aide wrote to the commission overseeing renovations that plans should be laid for "alterations at basement level" in the White House with "protective characteristics," Robert Klara writes in The Hidden White House. The extent of the renovations remain, for the most part, hidden.
Even during the Nixon years, when there were a rash of demonstrations across Washington, DC, use of the bunker was rarely acknowledged.
Nixon White House Counsel John Dean writes in his book, Blind Ambition: The White House Years, that when he was first introduced to the President's bomb shelter, he was told it was ideal for monitoring political demonstrations. Dean says he returned there only once: for a secret screening of a pornographic movie portraying Tricia Nixon's wedding to Ed Cox, in drag. Several White House officials watched the film in order to determine if legal action was needed.
Despite the fact that the bunker existed, presidential historian Timothy Naftali says the plan before 9/11 was always to remove a president from the White House instead of having him hunker down.
The terrorist attacks, however, introduced a threat where there might not be enough advance notice to move the president.
"In the Cold War, there was going to be some warning of a Soviet nuclear strike. It wouldn't be a lot of warning, it would be a few minutes at the shortest. But you would have a warning," Naftali said in an interview with CNN. "The President had time to leave the White House. ... After 9/11, I suspect, with an attack that came from within the United States, there was no longer a sense there would be enough time to get the president out of the building."
The terrorist attacks on September 11 are the most notable and recorded instance of the White House bunker being used for cover for the West Wing.
According to Lt. Col. Robert J. Darling, after the West Wing learned about a hijacked plane en route to Washington, DC, they were rushed into the bunker.
"At 9:45 all of these loud speakers blared to life that we didn't even know existed. They said evacuate the White House, evacuate the Eisenhower Executive Office Building, everybody secure your classified equipment and go to the alternate sites," Darling recalled during a talk with the Arlington Historical Society. "Everybody who was in the West Wing was now forced underground into this bunker complex."
Laura Bush wrote in her memoir that the day of the attacks she was "hustled inside and downstairs through a pair of big steel doors" that closed and formed an air tight seal behind her.
"We walked along old tile floors with pipes hanging from the ceiling and all kinds of mechanical equipment. The PEOC is designed to be a command center during emergencies, with televisions, phones, and communications facilities," the former first lady wrote.
According to Graff's book Raven Rock, it was midday on September 11 that Vice President Dick Cheney would complain about the connectivity in the workspace to National Security Council member Richard Clarke: "The comms in this place are terrible."
"Now you know why I wanted the money for a new bunker," Clarke responded, months after Bush had scrapped plans for expansion.
Photos released in 2015 by the National Archive show members of the Bush administration talking in the President's Emergency Operations Center beneath the White House around a long conference table with two televisions. Though Bush was in Florida during the attacks, and later flew on Air Force One that day to an undisclosed location, he was rushed to the bunker later that night after returning to Washington, DC, when there was another perceived threat.
It wasn't until 2010 that questions surrounding the maintenance of the White House's network of underground bunkers came up again. A massive underground construction project, with a projected cost of $376 million, was speculated to include some kind of renovation to the system of bunkers at the White House, Graff says, with large fences blocking the public's view to the project and no discernible changes once the construction was cleared out.
Construction officials told CNN at the time that the construction was "underground work" to fix electrical and plumbing problems.
Graff points out that this time the bunker was used, the response to the perceived threat is different than usual.
"Many presidents have weathered many protests and many extensive wide-scale protests over the years without being rushed into the bunker. And that is a tremendous statement about how something was different on Friday night," Graff said.
History may reflect, Naftali says, that the President's response shows how little he understands about the nature of the demonstrations. The protesters weren't demonstrating to create violence, they were protesting against it, Naftali says.
"I think that the public would respect a president that went into a secure area if the public shared the sense of threat and danger. But the reason the President is getting criticized, and the reason the President is backtracking and trying to deny that he went into the bunker, is that his perception of the threat and of the danger to American national security doesn't square with most people's," Naftali said.
"I don't think the American people like the idea that their president is afraid of them. And why should they?"