F-15s racing toward Seattle create sonic booms heard across region

Happened about half an hour ago. I heard two booms... the first one was louder and shook the hotel where I was staying while the second one was softer and didn't do much of anything. The first boom was muffled because I had the windows closed, but sounded like an explosion.

http://www.komonews.com/news/local/100921834.html