A City Council hearing on Tuesday examined the apparent rash of heat and hot-water outages at NYCHA developments after the “bomb cyclone” of early January.

One elusive element of this story has been how prevalent these problems have been. News reports indicated a wave of them, but NYCHA contended that the vast majority of its 400,000 residents continued to receive normal service. According to this map by the Pratt Center for Community Development, which the authors warn might not by comprehensive, the issues have not affected most NYCHA properties but have struck some in each borough.

Pratt’s testimony follows the map.