"The New York City Housing Authority (NYCHA) is a government agency that provides public housing for low and moderate-income residents throughout the five boroughs of New York City. NYCHA also administers a citywide Section 8 Leased Housing Program in rental apartments. Many of its facilities are known popularly as """"projects,"""" or """"developments."""" As a security measure, these premises are patrolled by the NYPD Housing Bureau. A total of 9 """"PSA's,"""" or Police Service Areas, patrol each borough except Staten Island, which has a separate unit from the Housing Bureau command, known as the """"SIHU"""" or Staten Island Housing Unit.   In one of his first public appearances since Superstorm Sandy battered public housing, New York City Housing Authority Chairman John Rhea defended the work of his agency while admitting that a great deal had gone wrong in NYCHA's response and saying much must be done to prepare for the next disaster.  "