What was that BOOM ?

Did you hear the recent unexplained BOOM! I did! It was about 7:30 one evening and I had all my homes windows open ... my husband and I both looked at each other and said "what was that"? No aircraft around, no sirens followed but we soon found out that many residents along the coast of VA also heard (and felt) the BOOM! Since then, I have heard multiple theories: the US military conducting "top secret" missions, a small offshore earthquake, a meteor, a sonic boom and my favorite "seneca guns". What is seneca (or barisol) guns? It's basically a word to describe unexplained sounds, much like what we heard, that has no rational explanation, yet. These apparently have taken place periodically along coastal communities for hundreds of years. Hmm, works for me. There are so many things in life here on earth that we still don't understand. I heard the 8th grade class at Kemps Landing Magnet came up with the "seneca guns" theory first, good work kids, keep expanding those minds.