The late Wall Arch, Arches National Park, Utah. Wall Arch collapsed either Monday, August 4th, or Tuesday, August 5th, 2008.
I was honored to be there March '08 with my 10 year old son for his first trip to the park. This photograph of Wall Arch was taken March 16, 2008 at 9:26am. It's now gone forever, and this photograph just became priceless to me.
Here's a link to the AP story on-line.