Hajile
...that in one of the first tests of Hajile, an experimental British World War II retrorocket system, a gigantic block of concrete was dropped through the roof of the workshop from 2000 ft?
...that in one of the first tests of <b id="mwCIc"><a href="./Hajile" id="mwCIg" rel="mw:WikiLink" title="Hajile">Hajile</a></b>, an experimental <a href="./United_Kingdom" id="mwCIk" rel="mw:WikiLink" title="United Kingdom">British</a> <a href="./World_War_II" id="mwCIo" rel="mw:WikiLink" title="World War II">World War II</a> <a href="./Retrorocket" id="mwCIs" rel="mw:WikiLink" title="Retrorocket">retrorocket</a> system, a gigantic block of <a href="./Concrete" id="mwCIw" rel="mw:WikiLink" title="Concrete">concrete</a> was dropped through the roof of the workshop from 2000<span id="mwCI0" typeof="mw:Entity"> </span><a href="./Foot_(unit)" id="mwCI4" rel="mw:WikiLink" title="Foot (unit)">ft</a>?