We first brought you the story of a deadly plague diagnosis in Flagstaff earlier this week. A patient arrived at the emergency room and lost their life to the pneumonic plague. Meanwhile, health officials are still searching for the source.

FLAGSTAFF, Ariz. — A resident of northern Arizona has died of pneumonic plague, health officials said Friday. Plague is rare to humans, with on average of about seven cases reported annually in the U.S., most of them in the western states, according to federal health officials.