More information about the accident in a Georgia poultry plant that killed six workers on Jan. 28 has become available, but the federal agency investigating the case says a full accounting is years away.

The accident occurred at a poultry processing facility of Foundation Foods Group, previously known as Prime Pak Foods, in Gainesville, Ga. A discharge of liquid nitrogen used for cryogenic freezing killed five workers on the scene, with another dying in a hospital. Nine more were hospitalized, three critically.

Details have been sparse, but the casualties appear to have been caused by direct contact with the liquid nitrogen. A 911 caller from the plant said, “Oh my God. I’m standing with a guy who’s been frozen,” according to the Atlanta Journal-Constitution.

The U.S. Chemical Safety and Hazard Investigation Board said at a press conference shortly after the tragedy that it may take years before they can issue a full report. However, on Feb. 7, the agency revealed that the plant had been experiencing “conveyor issues” that resulted in the accidental release of liquid nitrogen from a flash-freezing bath. Plant maintenance personnel had reported a low liquid level in that bath, according to the AJC.