Two construction company officers in New York City have been indicted on charges of manslaughter, assault and reckless endangerment relating to the partial collapse of a building project last May that killed one worker and seriously injured three more, reports The New York Times.

Charged were Michael Tam, owner of Tamco Corporation, and his foreman, Ken Ai. Basic safety precautions were ignored at the site, and a system to support load-bearing walls that would have prevented the collapse was not installed, according to investigators.

Prosecutors contend that the two officers of the company knew that the 92-year-old building was unstable, and they had ignored warnings from experienced construction industry personnel.

Most of the 20 or so workers at the site were illegal immigrants, according to Robert Morgenthau, the Manhattan district attorney. The worker who was killed, Antonio Romano, 41, had recently immigrated from Mexico.

Tam pleaded not guilty to the charges, and at press time Ai's arraignment had been delayed.