What is the 'White House Big Dig'? Secret behind the mysterious structure built after 9/11 attacks revealed

The White House journalists, at the time, were told by officials that it was just standard utility upgrade construction.

Just as President George W Bush was set to complete his term, satellite images captured a mysterious white structure on the White House grounds, south of the West Wing in July, 2007. The unusually large structure remained on the grounds for nearly two years under the Bush administration with journalists beginning to question its purpose as no one ever saw it being built.

According to reporters, the structure — which looked like a shed — just appeared on the grounds one day. The White House journalists, at the time, were told by officials that it was just standard utility upgrade construction. However, there was much more to it, according to History's documentary The Secret of the White House.

Reporters again began asking questions, considering the amount of steel and concrete going into the construction near the West Wing of the White House. (Getty Images)

The mysterious white box continued to stand near the West Wing as the newly-elected President Barack Obama came into the White House in 2009. The structure was described as two-storeyed with corrugated metal on the outside with a few vents in the ceiling and a door.

As the speculations were dying down,  a large green plywood fence went up along the West Wing almost overnight in 2010. This led to extensive coverage of the mysterious construction at the White House, which was referred to by the media as the 'White House Big Dig.' Reporters again began asking questions, considering the amount of steel and concrete going into the construction, it fuelled speculations that what was really going on was the construction of a  secret underground lair.

The General Services Administration, however,  released a statement saying that the recent construction was to upgrade electrical systems and air conditioning units. Investigative reporters were told that the Big Dig would cost approximately $376 million.

The people working at the construction sites were properly vetted by and were strictly instructed to not talk to the reporters. (Getty Images)

"People who were working on it were under very strict instructions to not talk to the reporters," a former AP White House correspondent, Mark Smith, who worked extensively on the issue said, adding that even the company name and contact information on the construction equipment were taped over to maintain secrecy. On September 13, 2012, the fence and the white box disappeared as mysteriously as it had been set up and no one in the White House mentioned about it again.

With little knowledge about the actual purpose of the construction, the makers of the documentary began digging into the history of the White House and found their answers. The latest construction began soon after the horrific 9/11 attacks.

(SEPTEMBER 11 RETROSPECTIVE) Smoke pours from the twin towers of the World Trade Center after they were hit by two hijacked airliners in a terrorist attack September 11, 2001 in New York City. (Getty Images)

For the first time in nearly half a century, the White House was forced to go underground on September 11, 2001, into the Presidential Emergency Operations Center (PEOC). The PEOC, built by the 33rd US President Harry Truman in the wake of Soviet bombs — is a bunker-like underground structure which lies beneath the East Wing of the White House, it serves as a communications center and a secure shelter for the president and other protectees in case of an emergency.

As soon as the news of 9/11 attacks broke, the Vice President under the Bush administration, Dick Cheney, was nearly hauled by the Secret Service and taken down a tunnel into the PEOC, while President Bush was traveling at the time and took cover in the Air Force One. At that crucial time, Bush reportedly could not get hold of his wife over the phone and neither could Cheney get hold of the president from the PEOC for a long time. Bush was eventually rushed to the PEOC later that day, however, the leaders were out of touch with everything going on outside with no computers and dated phones in the bunker.

U.S. Vice President Dick Cheney (R) Speaks To President George W. Bush By Phone September 11, 2001 Inside The Operations Center At The White House After The Terrorist Attacks In Washington And New York. With Cheney Are Staff Members, Including Presidential Counselor Karen Hughes (L) And National Security Adviser Condoleezza Rice (C). (Getty Images)

The incident raised serious questions about the standards of the emergency protocols and of the bunker, considering the US president should be able to transmit anywhere in the world in such situations but the leaders were left crippled. Reports state that ever since the incident, Bush and Cheney swore to never be that out of touch with the world again, suggesting an upgrade of the PEOC in tandem with the operations above ground.

In 2007, the Homeland Security through the National Preparedness Guidelines announced an upgrade of the internal security system, which included the White House. However, another clue — in the form of two big vents where the mysterious box was — appeared shortly after the construction was done. The suspicions again arose last year when a sinkhole was spotted near the West Wing of the White House lawn on May 22, 2018. Although White House officials said that it was because of incessant rain, excavation experts in the documentary said that it pointed to the construction of a tunnel underneath.

The long-kept secret of the most mysterious 18 acres in the world was later outed. (Getty Images)

The upgrade of the PEOC was just the beginning of something much bigger. Former Investigative Reporter with the Washington Post, Ronald Kessler, eventually found out through secret sources that the Big Dig was the construction of at least six-story-deep underground facility which can incorporate the entire West Wing, equipped with all the latest technology for it to operate and food supply to last for months. According to Kessler, the real cost of the dig was close to a billion dollars.

The long-kept secret of the most mysterious 18 acres in the world was later outed by National Security Expert William Arkin who said in the documentary that about a billion dollars were spent after 9/11 to build a new capsule underneath the White House, which was essentially the Big Dig.