Sixth Avenue subway line
... that during construction of New York City's Sixth Avenue subway line in the 1930s, workers had to build around various utilities and tunnels, including an existing railroad tunnel and an elevated line?
... that during construction of New York City's <b id="mwAlM"><a href="./IND_Sixth_Avenue_Line" id="mwAlQ" rel="mw:WikiLink" title="IND Sixth Avenue Line">Sixth Avenue subway line</a></b> in the 1930s, workers had to build around various utilities and tunnels, including an <a href="./Uptown_Hudson_Tubes" id="mwAlU" rel="mw:WikiLink" title="Uptown Hudson Tubes">existing railroad tunnel</a> and an <a href="./IRT_Sixth_Avenue_Line" id="mwAlY" rel="mw:WikiLink" title="IRT Sixth Avenue Line">elevated line</a>?