Public health workers are warning more visitors to Yosemite National Park this summer that they may have been exposed to a deadly rodent-borne disease.

Officials sent emails and letters on Wednesday to 1,000 people who stayed in tent cabins in Curry Village. That’s in addition to 1,700 Curry Village guests who had previously been sent such a warning.

It’s unclear whether authorities expanded the boundary or extended the dates of potential exposure.

The warnings came after a Pennsylvania visitor became the second park guest to die of hantavirus pulmonary syndrome. The disease can be transmitted through the feces, urine and saliva of deer mice and other rodents. At least one other person was sickened.

The guests being warned stayed in Curry Village’s tent cabins in June, July or August.