Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to. They were used to facilitate the city’s development in hilly areas. Students may be familiar with the Morningside Park retaining wall , present immediately East of the Columbia campus. Retaining walls facing streets are mapped and inspected. Not so retaining walls supporting soil at back yards. Because the NYC Building Department is not aware of the presence of most, they are not inspected and left to decay. A fatal collapse occurred in October 2020.
