Aug. 20, 2012 at 5:38 AM ET
Legendary country musician Willie Nelson has been hospitalized because of breathing problems, organizers told an audience in Colorado after the 79-year-old failed to show up for a concert.
NBC affiliate KUSA-TV reported that Nelson was scheduled to appear at a fundraiser for an animal shelter called the Denver Dumb Friends League.
An announcement to the crowd in Castle Pines, Colo., said Nelson suffered "from breathing problems due to the high altitude and emphysema" and taken to a nearby hospital.
A spokesperson for AEG Live, the promoters that usually handle Nelson's performances, offered no comment to KUSA-TV on Sunday.
Back in July, Nelson talked exclusively one-one-one with NBC 5 in Dallas-Fort Worth as he prepared for his annual Fourth of July picnic at Billy Bob's in the Fort Worth Stockyards.
Nelson told NBC 5's Scott Gordon he probably will never retire.
"I still enjoy coming out and playing music and as long as the people enjoy it and come see us, I see no reason to quit," Nelson said.
Nelson is scheduled to perform at the House of Blues in Dallas on Tuesday.