One consequence of the the 9/11 attacks was a greater awareness of continuity-in-government issues. There was an effort (now moribund) to amend the Constitution and provide for the appointment of House members in case a large number of them were killed in an attack on the Capitol. Under current law, members of the House who die cannot be replaced until an election is held, and there would be a substantial problem if the House could not muster a quorum while the special election of, say, two-thirds of the House was complete. (Indeed, this proposed amendment was the subject of my very first post on CoOp.)
Nobody, though, has thought much about what would happen if someone bombed the Supreme Court and took out most of the Justices. Here the issue is not the time it would take to nominate and confirm replacements. Cases can be held over until a full bench is present. Instead, the problem would be that such an event would give the President an unprecedented (at least since George Washington) opportunity to stack the Court. I would hope that an informal arrangement would be made in that dreadful circumstance to say that the party affiliation of the new Justices would match what was there prior to the bombing. Perhaps there should be some thought to establishing a provision (not unlike the Twenty-Fifth Amendment) that would formalize that idea.