It’s been clear for weeks that Amazon faces an unprecedented challenge in coping with the fallout from COVID-19. With tens of millions of Americans now dependent on online delivery for their food, medicine, and other essential items, the nation’s No. 1 e-commerce company is buckling under increased demand. And as fulfillment center employees are diagnosed with the virus across the country, Amazon’s already-restive workforce has escalated its efforts to win better pay and safer working conditions. Among other things, employees at affected locations have simply walked off the job.