The Climbing Wall under the Manhattan Bridge is getting a protective shield according to the administrators for the Brooklyn Bridge Park. It appears that the City is taking seriously the danger of falling debris from the Manhattan Bridge. The City is in the process of issuing policy guidelines for the utilization of public spaces underneath elevated structures. This is a welcome development which AEA should take some credit for after bringing this issue to the attention of the City. See the below article for more details. 

Manhattan Bridge debris shutters area (AM New York)