The hantavirus warning hit Yosemite National Park hard over the Labor Day weekend.

Operators say there was a 20 percent cancellation rate for lodging in the park, The Associated Press reported. Yosemite is typically sold out for Labor Day weekend. Most of the cancellations were in Curry Village where officials say as many as 10,000 campers could have been exposed to the virus this summer.

Six cases of hantavirus with two deaths have been linked to the campground at Yosemite.