En route to <a href="https://en.wikipedia.org/wiki/Lebanon" id="mw9g" rel="mw:WikiLink" title="Lebanon">Lebanon</a>, two Israeli <a href="https://en.wikipedia.org/wiki/Sikorsky_CH-53_Sea_Stallion" id="mw9w" rel="mw:WikiLink" title="Sikorsky CH-53 Sea Stallion">Sikorsky CH-53</a> troop-transport helicopters <a href="https://en.wikipedia.org/wiki/1997_Israeli_helicopter_disaster" id="mw-A" rel="mw:WikiLink" title="1997 Israeli helicopter disaster">collide in mid-air</a> over northern Galilee, Israel, killing 73.