ATLANTA (AP) — Federal workplace safety officials are proposing nearly $1 million in fines against four companies following a January liquid nitrogen leak that killed six workers at a Georgia poultry processing plant.

U.S. Labor Secretary Marty Walsh announced citations and fines by the U.S. Occupational Safety and Health Administration on Friday.

"Make no mistake, this was a very preventable tragedy," Walsh told reporters.

He said the penalties imposed in the case were "relatively large but that is not enough." He said many companies simply write off OSHA fines as the "cost of doing business"...