What causes boomers in Taubaté?

AgoraVale.com.br : Sua Cidade na Internet : Taubaté: moradores se assustam com nova e misteriosa explosão e tremor de casas on Agoravale

Um novo e misterioso estrondo assustou os 280 mil habitantes de Taubaté na manhã de ontem, quarta-feira (14).

The 280k inhabitants of the city of #Taubaté want to know where the booms are coming from that shake houses. One hit yesterday, similar to the first one last November. No one seems to know what is causing them.

We work in this city also, as well as our home in #SJCampos. It’s about 30 minutes away from us. I’d like to cause some noise there, too, but with an identifiable sound and source. #Brazil