Willie Nelson never showed up at a fundraiser he was supposed to appear at in Denver Saturday—because he went to the hospital instead. "I was told Willie woke up and had trouble breathing, so he was taken to the hospital," the host of the fundraiser, which was to benefit a pet shelter, tells the Denver Post. The rest of Nelson's band showed up at the event, apparently unaware of their frontman's health issue, 9News reports. The crowd was told that the singer's problems were tied to "the high altitude and emphysema." Asked how Nelson was doing, his promoters offered no comment. (More Willie Nelson stories.)