What would you do?

We just accidentally found out that my husband's brother recently got divorced. We live in a different state but occasionally look through the online edition of my husband's hometown. Under marriages/divorces there it was. My SIL chose a combination name when they got married and combined with all the other information provided it's unique enough to know it's them. The problem is even though the marriage was under the weather from the beginning we actually thought things had improved in the last two years. There was nothing indicating this was going on and nobody let us know that this was coming. We were led to believe everything is just dandy. And a divorce isn't exactly finalized over night.

My question is, how would you handle this? Should we just pretend we don't know about it? My in-laws don't know we look at the local newspaper from time to time. It's not like they could have expected us to find out this way...