Two construction companies and two supervisors were charged with manslaughter and other crimes in the death of a worker who was crushed this year, authorities said Wednesday in announcing a task force to investigate misconduct in the booming building industry.

District Attorney Cyrus R. Vance Jr., the New York Police Department and the city's Department of Investigation announced the charges in the April death of Carlos Moncayo, an employee with Sky Materials Corp. Moncayo was in an unsecured trench at a building site in Manhattan's trendy Meatpacking District when it caved. The building was once home to the restaurant Pastis and is now being developed into a Restoration Hardware retail store.

Vance said the worker's death was "tragic, but it was also foreseeable and avoidable." He said repeated warnings were issued about safety hazards at the site in the months, weeks and even minutes before Moncayo's death but company supervisors Wilmer Cueva and Alfonso Prestia allowed workers to continue.

Sky was a subcontractor hired to excavate the area, and Harco Construction LLC is the general contractor on the site, officials said. Any excavations deeper than 5 feet must be fortified before workers are allowed inside, and the area was that deep or deeper, officials said. Inspectors first noticed in February the site was unsafe and, despite meetings with the defendants, safety practices did not improve, officials said.

Then on April 6, an inspector went to the site and told Cueva and Prestia the area was unsafe and to get the workers out immediately. Nearly two hours later, Prestia instructed the crew in English to get out, but many workers understood only Spanish and didn't get out, officials said. Just moments after Cueva finally called out to the workers in Spanish to get out, the trench collapsed, killing Moncayo, authorities said.

"What our detectives quickly learned was that this construction site was also a crime scene," police Commissioner William Bratton said.