Was back this weekend and played at Canterbury. They lost 3.5 greens; sounds similar to Hazeltine. They lost #8 (it is barely alive; and significant parts of the #5, #6 and #16 greens. The root strcuture was not deep enough on all the greens and these greens have very bad drainage and the wet weather and severe heat caused the grass to die. They are going to aerate much more frequently, add drainage to these greens and remove lots of trees near the greens.
Really too bad as the are some of the nicest greens normally that I have ever played. On a side note, they need to cut down a ton of trees at teh course. It really seems over grown now. I love the course and was very bummed to see the damage this weekend. Of course, they got about 2 inches of rain yesterday in a severe storm.