A crane mechanic who was co-defendant in a negligent homicide case stemming from a fatal 2008 tower crane collapse in New York City quietly changed his plea to guilty last month and has promised to help prosecutors convict his former boss, who owned the crane and its rental firm, New York Crane.

The Oct. 5 plea change in New York State Supreme Court by Tibor Varganyi, 65, came about one month before his trial and that of his former boss, James F. Lomma, 65, were set to start. New York County Supreme Court Judge Thomas Farber granted Varganyi's plea change request in a closed hearing but declined to seal hearing records. “I will do nothing to advertise this to anybody,” he said. “I am also not doing anything to hide it.”

According to the court transcript, Lomma allowed, even urged, Varganyi to hire a Chinese firm to handle manufacture and welding of a replacement crane bearing in order to expedite work, although the firm's track record in such work was not verified. “Lomma never asked you any questions about this company and never required you to make any inquiries regarding its reputation or the quality of its work,” the court asks Varganyi in the plea document.

The bearing later broke and the crane's upper portion collapsed, killing union crane operator Donald C. Leo and another worker, Ramadan Kurtaj.

Varganyi signed a cooperation agreement to testify against Lomma and the firms in exchange for a probable non-jail sentence, transcripts indicate.

Prosecutors indicted Lomma, Varganyi, New York Crane and another Lomma-owned firm in 2010 on charges of second-degree manslaughter, second-degree assault, criminally negligent homicide and second-degree reckless endangerment, with a 15-year jail sentence possible on the first charge. Defendants pleaded not guilty to all the charges. Varganyi is set for sentencing by at least next March.

Varganyi's lawyer Matthew Brief declined to elaborate on the transcripts, and Lomma attorney Paul Shechtman did not reply by press time.