Work started on the bridge on June 11 , 1890 , with excavation of the bridge 's abutments finished a week later . By March 20 , 1891 , only the approach to the bridge remained to be completed . The bridge , officially , was opened on June 1 , 1891 , at the same time as the incline . On March 17 , 1936 , nearly 4,000 people crowded on the approach , the bridge , and numerous boats to escape to higher ground via the incline as Stoneycreek and Conemaugh Rivers overflowed their banks . The floodwaters continued downstream and eventually reached Pittsburgh
overflowed their banks
Johnstown flood of 1936
Inclined Plane Bridge