“I’m treated like public enemy No. 1, all because I did the right thing,” Mr. Greenberg, 39, said.

He is suing the contractors who employed him, Bovis Lend Lease and the John Galt Corporation, accusing them of retaliating against him for telling the truth. Bovis, in court papers, has denied his claims. Galt has yet to file its court papers, and declined comment.

Image Marshal Greenberg, who worked at the Deutsche Bank building, behind him, is the son of a notorious figure in the demolition industry. Credit... Ozier Muhammad/The New York Times

But in interviews, a safety inspector from the job, an investigator affiliated with the inquiry by the Manhattan district attorney’s office, an integrity monitor for the project and several co-workers corroborated much of Mr. Greenberg’s account, including his safety concerns and the harassment he suffered.

“They thought he opened his mouth,” said Rodney Bettis, a fire-watch officer who worked at the building. He described the abuse Mr. Greenberg suffered as “pretty constant.”

Mr. Greenberg entered the construction industry 10 years ago with the help of his father, Harold Greenberg, a notorious figure in the demolition industry who has prior convictions for bribing an inspector and bid rigging. As an operating engineer, his son, Marshal, was in line for some of the highest paid union jobs in construction. Initially he worked for his father’s companies.

In 2005, when the Deutsche Bank demolition began, a company associated with the elder Mr. Greenberg, Safeway, was hired by Bovis to strip away hazardous materials at the site. But the company was soon dropped, in part because of concerns about Harold Greenberg’s role and in part because of an accident at an unrelated construction site.

Bovis replaced Safeway with John Galt, a company that had little experience but whose leaders included two former Safeway executives. Marshal Greenberg went to work for Galt in 2006, assigned to operate one of four hoists, or elevators, at the building. It was the first time he had taken a job outside his father’s purview.

The demolition of the bank building, which had been heavily damaged in the Sept. 11 terrorist attack, became the most heavily regulated project in the city. Officials believed the building was filled with a toxic stew of contaminants that would have to be abated before demolition could proceed.