POSTVILLE, Iowa — It wasn’t until their colleagues began to disappear that workers at Agri Star Meat and Poultry realized there was a killer in their midst.First came the rumors that rabbis at the kosher plant had been quarantined. Then a man who worked in the poultry department fell ill. They heard whispers about friends of friends who had been stricken with scorching fevers and unbearable chills — characteristic symptoms of the novel coronavirus.Where was the contagion coming from?No one would say. Not Agri Star’s wealthy owner, who didn’t shut down production lines after cases were...…POSTVILLE, Iowa — It wasn’t until their colleagues began to disappear that workers at Agri Star Meat and Poultry realized there was a killer in their midst.First came the rumors that rabbis at the kosher plant had been quarantined. Then a man who worked in the poultry department fell ill. They heard whispers about friends of friends who had been stricken with scorching fevers and unbearable chills — characteristic symptoms of the novel coronavirus.Where was the contagion coming from?No one would say. Not Agri Star’s wealthy owner, who didn’t shut down production lines after cases were...WW…