The first person I knew was Barry Smotroff, a science fiction fan who lived in New York City, who was killed on July 29, 1976, apparently in a robbery. See a link to a photo of him. Here's a link to a story about Barry. I'm not sure exactly how I met him - either during a visit to New York to meet fans, or possibly at a science fiction convention or two.
The second person I knew was Ben Blutstein, who was murdered on July 31, 2002, at the Hebrew University in Jerusalem by a terrorist who left a bomb in the Frank Sinatra cafeteria. Eight other people were killed in the same attack. I did not know any of them, but friends of mine in Jerusalem knew them. This was during the height of the second intifada.
Nine people - four Israelis and five foreign nationals - were killed and 85 injured, 14 of them seriously, when a bomb exploded in the crowded Frank Sinatra cafeteria on the Hebrew University Mt. Scopus campus shortly after 13:30. Hamas claimed responsibility for the attack.
The bomber left the bomb in an innocent looking bag packed with shrapnel in the cafeteria. The device was professionally prepared, possibly in one of the factories in the Nablus casbah, which the IDF has refrained from entering since Operation Defensive Shield after Passover.
Though classes were not in session, students were taking exams at the time of the blast, and the cafeteria was crowded with diners. There were also numerous students in the building registering for classes for the coming school year.
The cafeteria is also near the Rothberg International School, where about 80 pupils from the US and other Western countries had arrived to prepare for the fall semester.The murderers in this case were caught about two weeks later. They were also responsible for the Cafe Momento attack in Jerusalem on March 9, 2002, when 11 people were killed. The man who placed the bomb in the cafeteria was Muhammad Ouda, 29, who worked as a construction worker at the university.
Most of the injured were between the ages of 18 and 30. The explosion gutted the cafeteria.