Yosemite National Park officials told 1,700 past visitors in an e-mail blast today (Aug. 28) they may have been exposed to a rodent-borne disease that has claimed two lives.

Four people who spent time in Signature Tent Cabins at Curry Village around the same time in June have contracted hantavirus pulmonary syndrome, an illness spread by rodent feces, urine and saliva. Two of the four have died.

The mortality rate for the illness is about 33 percent, according to published reports.