As best I can tell Leo Ryan of California is the only U.S. Member of Congress murdered while in office. He was killed by members of the People's Temple in Guyana in 1978. What I'm looking for are how many died while in office.

I guess I could dig through each article on Wikipedia for all 113 Congresses and get the info but if anyone has the exact figures that would be helpful.

(My son, who's doing a unit on US Government, asked this when we were discussing why there are special elections. I thought it would make a good question here.)