At least six people were killed and a dozen hospitalized following a liquid nitrogen leak at a poultry plant in the U.S. state of Georgia, officials said on Thursday.

Five people died at the Foundation Food Group plant in Gainesville, about 100 kilometers northeast of Atlanta, before they could be taken to a hospital, and one died in the emergency room, the officials said. 

At least three of those hospitalized were reported in critical condition.

The injured included four firefighters who suffered respiratory ailments. About 130 other people were evacuated from the plant to a nearby church where they were medically evaluated, officials said.

The accident occurred at about 10 a.m. on Thursday, said Zach Brackett, a Hall County Fire Services spokesman.

U.S. Foundation Food Group Vice President for Human Resources Nicholas Ancrum called the leak a tragic accident and said early indications were that a nitrogen line ruptured in the facility.

Nitrogen, typically an inert gas, becomes a liquid when cooled to about minus 196 Celsius and is widely used in frozen food processing plants.

But at room temperature, it can expand into an odorless gas about 700 times its liquid volume, rapidly displacing oxygen in the air and lungs and causing unconsciousness and lethal asphyxiation, according to the University of Delaware. 

The Gainesville plant, which only became part of Foundation Food Group on January 1, processes raw chicken into products like chicken fingers and individual chicken cuts for restaurants and food service operations.

Last month, two workers at a Golden West Food Group plant in Los Angeles County lost consciousness and died following an apparent liquid nitrogen leak there, according to the Los Angeles County Fire Department.

(Cover: Emergency personnel gather outside of the Foundation Food Group site following a liquid nitrogen leak that killed six people in Gainesville, Georgia, U.S., January 28, 2021. /AP)

(With input from AP, Reuters)