A bronze wall plaque inside Loews’ Lincoln Square (where I saw Celine Song’s Past Lives in the late afternoon) commemorates the late Loews’ Capitol theatre (B’way at 50th or 51st). Built in 1919, the 5000-seater gave up the ghost in September 1968. For some reason the plaque says it was torn down in ‘67. 2001: A Space Odyssey opened at the Capitol on 4.3.68.
Wikipedia also has it wrong about the Capitol’s Cinerama conversion. The first Cinerama film to show there was the now completely forgotten The Wonderful World of the Brothers Grimm, which opened in August ‘62.