@darrok
I think he's talking about a suicide attacker flying an airplane into the Capitol
No, if you go up a couple more comments they were talking about blowing up the capitol building, not a 9/11 style kamikaze attack with an airplane.
The swearing in ceremony would actually not be an ideal time for such an attack either way.
https://www.inaugural.senate.gov/vice-presidents-swearing-in-ceremony/
The location of the Vice President's oath-taking ceremony has also changed since John Adams became Vice President in 1789. Today, the Vice President recites the oath on the Inaugural platform constructed on the West Front of the U.S. Capitol, prior to the swearing-in of the President. Until 1937, most Vice Presidents took the oath of office in the Senate chamber, prior to the President's Swearing-In Ceremony. This made the Vice President's Swearing-In Ceremony distinct and separate from the President's.
The president's swearing is usually done outdoors, on the capitol grounds, but not actually in the capitol building.
https://www.inaugural.senate.gov/presidents-swearing-in-ceremony/
Also, the key players wouldn't be at the capitol until literally minutes before the swearing in.
https://www.inaugural.senate.gov/procession-to-the-capitol/
By tradition, members of the Joint Congressional Committee on Inaugural Ceremonies travel to the White House to escort the President-elect, Vice President-elect, and their spouses to the Capitol for the Inaugural Ceremonies. After a brief meeting, the President-elect and the outgoing President will then proceed together to the Capitol for the Swearing-In Ceremonies. This tradition has endured, with few exceptions, since 1837, when Martin Van Buren and Andrew Jackson rode together in a carriage made from wood taken from the U.S.S. Constitution. The Vice President and Vice President-elect will follow, as will family members, cabinet members, and members of the JCCIC.