In <a href="https://en.wikipedia.org/wiki/Milwaukee" id="mwkA" rel="mw:WikiLink" title="Milwaukee">Milwaukee</a>, nine members of the <a href="https://en.wikipedia.org/wiki/Milwaukee_Police_Department" id="mwkQ" rel="mw:WikiLink" title="Milwaukee Police Department">Milwaukee Police Department</a> are <a href="https://en.wikipedia.org/wiki/Milwaukee_Police_Department_bombing" id="mwkg" rel="mw:WikiLink" title="Milwaukee Police Department bombing">killed by a bomb</a>, the most deaths in a single event in U.S. police history until the <a href="https://en.wikipedia.org/wiki/September_11_attacks" id="mwkw" rel="mw:WikiLink" title="September 11 attacks">September 11 attacks</a> in <a href="https://en.wikipedia.org/wiki/2001" id="mwlA" rel="mw:WikiLink" title="2001">2001</a>.