My wife and I heard the boom a little before 9 this morning in the River Rd area. The cats freaked out and we searched the house thinking something heavy had fallen somewhere. Eventually we shrugged and moved on.

But I just opened my RSS reader and saw there are 2 threads on the subject back on the reddit. Sounds like it was heard all over the city and shook some windows in areas. Here are the links: first thread, second.