Toronto's worst mass shooting
... that Toronto's worst mass shooting was committed by teenagers at a block party?
... that <b id="mwARQ"><a href="./Danzig_Street_shooting" id="mwARU" rel="mw:WikiLink" title="Danzig Street shooting">Toronto's worst mass shooting</a></b> was committed by teenagers at a <a href="./Block_party" id="mwARY" rel="mw:WikiLink" title="Block party">block party</a>?