What is going on? and has this happened before?

This has just been a horrible 7 days. Over the last week we had 3 celebrities p away. Those were Ed McMahon, Farah Fawcett, and Michael Jackson. I've now learned about legendary T.V. pitchman Billy Mays ping away this morning. So here is my question. What is going on? I don't remember 4 celebrities dying in such a short period of time and that brings up my other question, has this ever happened before?