Conversation so far:
Are there any other interesting aspects about the Ahmed Yassin article?
The Palestinian Authority declared three days of mourning and closed Palestinian schools.
What caused the closure of Palestinian Schools by the Palestinian Authority?
Ahmed Yassin was killed in an Israeli attack.
Who were Palestinians mourning when the Palestinian Authority declared three days of mourning?
Ahmed Yassin

Question: When did he die?
Self-contained rewrite: When did Ahmed Yassin die?