Mystery death at Russian plague lab triggers sweeping precautions as US watches closely

Russian authorities have quarantined a hospital and placed scores of people under medical observation after a 28-year-old employee at a Siberian plague research institute died from a mysterious case of pneumonia, fueling fears — still unconfirmed — that she may have contracted pneumonic plague.

Darya Shipilova worked at the Irkutsk Anti-Plague Research Institute of Siberia and the Far East. Russian health authorities say extensive testing found no evidence that her illness was caused by pathogens linked to her work...