President Donald Trump’s ambitious renovation of the White House East Wing may involve more than just a massive new ballroom, according to a new report by CNN. The project is now believed to include secretive construction work to rebuild or upgrade an underground bunker beneath the East Wing.

Trump has previously revealed plans to construct a 90,000-square-foot ballroom atop the historic East Wing, dramatically reshaping that section of the White House complex. The East Wing was reportedly demolished in October to make way for the development.

While the White House has never officially acknowledged the existence of an underground facility beneath the East Wing, it has confirmed that “top-secret” work is underway as part of the broader renovation. CNN reports that this classified portion of the project is linked to a subterranean bunker believed to be used for emergency protection and continuity-of-government operations.

The secretive nature of the underground construction has fueled speculation about its purpose, scope, and cost, though details remain classified for national security reasons.

The East Wing traditionally houses key offices, including those of the First Lady and White House social staff. Its demolition and replacement with a large ballroom — coupled with covert underground work — marks one of the most dramatic architectural changes to the White House in decades.

Neither the White House nor Trump has publicly commented on the reported bunker reconstruction.