So just to add a little bit more to this. Also, not trying to be critical here, it could happen to anyone.

www.airnav.com site is an awesome site. If you type in your nearby busy airport, then scroll down until you see “Sectional chart” on the right and click on the graphic. A box on the top left will allow you to toggle to any type of map, IFR WAC, SEC, but leave it on the default which is Hybrid VFR. Then find your glider port and zoom all the way down. It may surprise you (it did me) that there is little B747 jets at the offending intersections, and the altitudes listed near the glider symbols.

There is a jet at teddy intersection and 7000-17000 is noted. Traffic would have been higher up to 17000 msl if the winds were such that KORD was landing to the West that day.