Herman Jessor

Herman J. Jessor (June 15, 1894 – April 8, 1990) was an American architect who helped build more than 40,000 units of cooperative housing in New York City.

He included entrance foyers, eat-in kitchens with windows, and bedrooms with cross-ventilation, so working-class families without air-conditioning could benefit from natural breezes.

The roof had been built to support a vast playground/park above, with trees and grass upon hundreds of thousands of pounds of soil.

After the collapse on Friday night, January 15, 1999, the New York City Department of Buildings opened an investigation into other Jessor projects to test for durability.

[9] The investigation did not turn up any major design flaws, and cited convergence of many elements including several days of warm rain, followed by quick freezing, thawing, and refreezing, along with a stoppage in the drainage system combined with minor cracking of the concrete in the roof and the immense weight above.