Life's little mysteries

From the U.S. comes a tale of two cities - New York where a strange odour hung in the air, and Austin where birds didn't. Both are mysteries and big ones considering quite a few city blocks were closed in Austin where the bird bodies littered the streets. At time of writing (which is to say I'm not going on to the web to check out what's been happening with these stories) no apparent cause had been discovered for either of these ... but it is curious, isn't it. Is there something in the air?