The shooting today in Virginia raises a constitutional issue that comes up periodically and should be addressed with an Article Five amendment.
Suppose most of the members of the House of Representatives were killed in a terrorist attack (either domestic or foreign). There is only one constitutional way to replace these dead members--a special election called by each affected state for the vacancies. This process, though, would take months. In the interim, the surviving members of the House (even if there were, say, only twenty left) would be forced to act as the House and consider emergency legislation in the wake of that crisis. The Senate, does not face this problem. Deceased Senators can be replaced (under the Seventeenth Amendment) by an appointment from the Governor of their state, though state law can choose to require a special election instead.
Consequently, many scholars and members of Congress have proposed that the Constitution be amended to say that if a mass vacancy occurred in the House, then Governors would be able to appoint interim replacements. In 1960, such an amendment was proposed due to the concern was that a nuclear bomb would incapacitate the House. After 9/11, the proposal was revived in the wake of the failed attempt to blow up the Capitol.
These Article Five amendment proposals have never received the necessary support in Congress. Perhaps that is because the idea that all House members must be elected is considered sacrosanct. Or maybe it is because the thought that such a disaster would occur seems too far-fetched. Neither is true. Hopefully action can be taken before the crisis is upon us.