“While the expansive aboveground complex has drawn most of the attention, Trump revealed during a recent Cabinet meeting that there was another motivation for the construction.
He told Cabinet members there was a national security component to the project that was “supposed to be secret” and the military “wanted it more than anybody.”
“It was supposed to be secret, but it became unsecret because of people that are really unpatriotic saying things,” he said.
Shuffling through renderings of the project, Trump described the underground facility as having bulletproof glass and “drone-proof” roofs and ceilings.”
https://www.yahoo.com/news/articles/know-white-house-ballroom-bunker-200546113.html