She aborted the clutch about two weeks ago, leaving behind four eggs in a copper-lined rain trough. It's very possible the torrential rains we had a few weeks ago were simply too much for Idelle as the rising water surrounded her and the eggs.
A failed, first clutch is not uncommon and certainly explains the copulating I witnessed recently as the pair makes a second attempt at nesting this year. The birds have also gravitated over to one of the Pfizer buildings, perhaps attracted to what some say is a gravel roof.
Another twist in this story are reports of a third bird. Karen Tindall, who works in the Haymarket building on Michigan Avenue, across the street from Fifth Thirds, reports she saw a third peregrine recently in the area, something Jonathan Morgan (a local birder) witnessed a few weeks back.
I think it's safe to say the falcons are here to stay, and sooner or later they'll succeed with a brood and young will fledge. The question is exactly where and when that will happen.