The fungus that has already killed 6 million bats in the eastern US and Canada has been found in Kentucky’s Mammoth Cave National Park for the first time, reports the Los Angeles Times. A bat with white-nose syndrome was discovered in Long Cave, a 1.3-mile-long cave not linked to the 390-mile-long Mammoth Cave; it’s been closed to visitors for some 80 years. Mammoth Cave, however, will remain open, though officials worry about the highly contagious nature of the fungus and the fact that the disease can linger for decades in cave environments. The park began requiring tourists to walk on decontamination mats in 2011 after the disease was identified in Indiana, reports the Courier-Journal. “I am incredibly sad to report this,” said a Mammoth Cave National Park official. “A northern long-eared bat showing symptoms of white-nose syndrome was found in Long Cave in the park. The bat was euthanized on Jan. 4.” Lab tests confirmed white-nose syndrome. The fungus behind white-nose syndrome, known as Geomyces destructans, hits hibernating bats the hardest, causing them to fly outside in daylight and exhibit other unusual behaviours.