11 South LaSalle Street Building or Eleven South LaSalle Street Building ( formerly Roanoke Building and Tower and originally Lumber Exchange Building and Tower Addition or simply the Roanoke Building and Lumber Exchange Building ) is a Chicago Landmark building that is listed on the National Register of Historic Places and that is located at 11 South LaSalle Street in the Loop community area of Chicago , Illinois , United States . This address is located on the southeast corner of LaSalle and Madison Street in Cook County , Illinois across the Madison Street from the One North LaSalle Building . The building sits on a site of a former Roanoke building ( once known as Major Block 2 ) that once served as a National Weather Service Weather Forecast official climate site and replaced Major Block 1 after the Great Chicago Fire . The current building has incorporated the frontage of other buildings east of the original site of Major Block 1
Great Chicago Fire
Great Chicago Fire
Roanoke Building