HOPE, Ark. – Sixty employees were evacuated and eight sanitation workers were taken to a local hospital after an early morning ammonia leak at a Tyson Foods poultry processing plant in Hope.

“We’re investigating the cause of an ammonia refrigeration release early Saturday at our Hope, Arkansas, poultry plant,” Tyson spokesman Gary Mickelson said in a statement. “It happened just after 3 a.m. The plant was not in operation at the time, however, about 60 team members in the facility were evacuated. Eight sanitation workers were taken to the local hospital, seven of them were released and one was transferred to a Little Rock hospital for treatment.”

Mickelson added that the leak has been contained and operations and safety specialists with Tyson have launched an investigation.