FAYETTEVILLE (AP) — Two employees at an eastern North Carolina industrial operation died at the site on Sunday, authorities said. Sheriff’s detectives were investigating what happened.

Cumberland County deputies arrived Sunday afternoon at the Valley Proteins Inc. plant in Fayetteville after the employees were found unresponsive, according to a Cumberland sheriff’s office news release. The workers’ names weren’t immediately released, pending notification of family members.

Valley Proteins collects, renders and recycles fat and bone trimmings, meat waste and used cooking oil, according to the company’s web site. The Winchester, Virginia-based company has locations on the East Coast and in the southern U.S.

Firefighters evacuated the Fayetteville building, and North Carolina’s Occupational Safety and Health Administration emergency response team also came to the scene, the sheriff’s release said.