A key congressional panel launched an investigation this week into the wave of COVID-19 infections that killed hundreds of workers at meatpacking plants nationwide last year and highlighted longstanding hazards in the industry. …To date, more than 50,000 meatpacking workers have been infected and at least 250 have died, according to a ProPublica tally. … [The congressional investigation] will examine the role of JBS, Smithfield Foods and Tyson Foods, three of the nation’s largest meat companies...