...this was posted on the utah govt site:
WANTED: We need volunteers to help monitor and rescue young-of-the-year peregrine falcons during their flight training period.
When & Where: The flight training period could begin as early as July 4. If you'd like to help, please join us for Salt Lake City peregrine falcon field trip and volunteer orientation meeting at 6:00 p.m. on Tuesday, June 28. We will meet just east of the Joseph Smith Memorial Building, which is south of the tall Church Office Building
...and, i was just looking in at the chicks on Camera 2, they are all sitting in the sheltered portion of the box, out of the hot sun; I can't really distinguish any real size differences between them, although one does appear a little bit smaller than the others, but it also seems to have more down left than the others - the last hatch, perhaps?