The construction site at 9-19 Ninth Avenue on April 6, 2015, the day 22-year-old construction worker Carlos Moncayo was crushed to death. View Full Caption Manhattan District Attorney's Office

CIVIC CENTER — Two construction supervisors, along with the companies that employed them, were charged with manslaughter Wednesday for the death of a 22-year-old worker who was "buried alive" at a construction site in the Meatpacking District, according to Manhattan District Attorney Cy Vance.

Wilmer Cueva, 50, and Alfonso Prestia, 54, and their respective employers Sky Materials and Harco Construction ignored months of warnings about the hazardous conditions at the site, Vance said, including two hours of pleading from an inspector the morning of Carlos Moncayo's death.

Moncayo was working in an almost 14-foot-deep trench that should have been reinforced at the time of the accident, Vance said. Though an inspector warned Prestia and Cueva to get Moncayo and other workers out of the trench for hours before the fatal accident, beginning when the trench was 7 feet deep, they did not order him out until moments before it caved in.

Wilmer Cueva, left, and Alfonso Prestia, right, are arraigned Wednesday afternoon. DNAinfo/Ben Fractenberg

"The indictment alleges that Harco Construction, Sky Materials, Prestia and Cueva knew full well the risks of sending workers into an unfortified trench," Vance said. "But, tragically, they kept doing it anyway, despite a constant drumbeat of warnings conveyed in email upon email, emergency meeting after emergency meeting."

Construction at 9-19 Ninth Ave. — where the building that once held the restaurant Pastis is being developed into a Restoration Hardware flagship store — was months behind schedule, according to Department of Investigation Commissioner Mark Peters, whose agency also investigated the incident. Workers were rushing to prepare for a concrete truck due in that day.

Permits were issued for the project back in December 2014.

Moncayo and Cueva were employed by Sky Materials for excavation at the site. The kind of work Sky Materials was subcontracted to do is among the most hazardous in the construction business, Vance said.

As early as February 2015, an independent inspector hired to monitor the site found excavation methods "severely lacking with respect to workers' safety," Vance said.

From his first day on the job, Vance said, the inspector complained that "Cueva was ignoring basic safety standards," and that Sky "frequently didn’t use any fortifications at all on its trenches."

Sky declined to comment.

Manhattan District Attorney Cy Vance Jr. announces charges against two construction supervisors Wednesday. DNAinfo/Rosa Goldensohn

Harco employees, including Prestia himself, repeatedly warned higher-ups at the company that safety rules were being regularly flouted at the site, according to Vance.

In late February, a Harco superintendent with decades of experience wrote in an email to Harco management that Cueva "is totally reckless, and eventually he will get someone hurt."

"At this point, I no longer want him on the job," the superintendent wrote.

In another email, he said Prestia was also concerned about the excavation practices.

"This is what me and Alfonso are talking about. We’re not making it up. Men are in this hole with concrete and dirt above their heads.”

He pleaded with his Harco supervisors again on March 11 to request Cueva be removed because of "excavation hazards."

The next day, Harco management ordered employees to stop sending such emails, threatening that someone could be fired if any more complaints were made.

The superintendent resigned, Vance said.

Harco's lawyer Ronald Fischetti denied that the company told workers to stop emailing safety complaints, and insisted the company was not aware of safety issues at the site.

"My clients state this this a tragic accident but they're not responsible for it," Fischetti said on Wednesday.

On April 1, an inspector told Cueva and Prestia, just days before Moncayo was killed, that they either had to put in protections for an upcoming excavation, or figure out how to do it without sending workers into "unprotected trenches."

But on April 6, an inspector arrived at 9:45 a.m. to find an unfortified 7-foot trench.

The inspector rushed to find Prestia, who was apparently inside a trailer with no sightline to the pit. The inspector warned him that workers should not be in the trench, according to the district attorney, and gave Cueva the same instructions.

But less than an hour later, about 10:35 a.m., the inspector found four workers inside the pit, which had grown to nearly 14 feet deep and was still unfortified.

The inspector told Cueva the workers had to evacuate the trench immediately.

But according to Vance, Cueva ignored the inspector's advice.

For nearly an hour, the inspector raced back and forth between Prestia and Cueva, trying to persuade one or the other to get the workers out of the pit, Vance said. By 11:15 a.m., the inspector had apparently warned them each twice, to no avail.

Prestia did not leave his trailer until 11:30 a.m., Vance said, almost a full two hours after the inspector's first warning. He then told the workers, in English, to get out of the pit.

But the workers, who primarily speak Spanish, kept working.

The inspector finally convinced a Sky employee to heed his warnings, and the employee persuaded Cueva to alert the crew in Spanish.

That was about 11:50 a.m., Vance said. It was too late.

Moments after Cuevo gave the warning in Spanish, the pit collapsed around Moncayo, crushing him.

He was "buried alive," Vance said.

The youngest of seven siblings, Moncayo was just about to celebrate his 23rd birthday, Vance said. He lived with his sister and her young son in Queens and was known as a doting uncle. He was undocumented, as were other workers at the non-union site, Vance said.

The Department of Buildings suspended Harco's New York City registration for "a pattern of risky behavior" on July 20, shutting down its worksites citywide, they said.

The building was purchased by William Gottlieb Real Estate and Aurora Capital Associates last year.

William Gottlieb Real Estate declined to comment through an attorney, who said that Aurora Capital has led the actual development since the purchase.

Messages to a vice president at Aurora Capital were not immediately returned.