Among those I could see going dark:
- Navy Pier, except for its ferris wheel still blazing into the night (600 East Grand Avenue)
- The John Hancock Center (875 North Michigan Avenue)
- Willis Tower (233 South Wacker Drive)
- Aon Center (200 East Randolph Street)
- Marriott Chicago Downtown Magnificent Mile (540 North Michigan Avenue)
- The Park Tower (800 North Michigan Avenue)
- Grand Plaza (540 North State Street)
- 55 East Erie (55 East Erie Street)
- NBC Tower (200 East Illinois Street)
- Chase Tower (10 South Dearborn Street)
- The Clare at Water Tower (55 East Pearson Street)
I assume that the Wrigley Building and Tribune Tower participated because they participate in most everything.
The Marriott always has trouble with its sign, so it ended up darkening some of the letters early in the evening (spelling out "Mot").
Trump International Hotel and Tower was also dark, but not for the occasion. In spite of what the Chicago Tribune reported, it does not light up at night at all, so this was one of the few occasions when it actually looked appropriate in the night skyline.
Some buildings didn't join in:
- Millennium Centre (33 West Ontario Street)
- 300 North LaSalle (300 North LaSalle Drive)
- 353 North Clark (353 North Clark Street)
- The Hyatt Regency Chicago (151 East Wacker Drive)
- Museum Park (1215 South Prairie Avenue)
- The Fordham (25 East Superior Street)
- Millennium Park (337 East Randolph Street)
As you can see in the photos below, 300 and 353, and the Hyatt are the brightest things in the Chicago skyline, and conspicuous for their illumination when all of their neighbors have gone dark. As always, you can click to enlarge the pictures and see the offenders.