Around 6:30 I head a very big boom. I thought it was a thunderstorm but it was sunny out and suddenly tons of sirens started to wail. Doesn't sound good. Went downstaris and can see smoke uptown. I overheard some people on cell phones talking about three explosions on 38th street. Cops have blocked off the street. No news, nothing online - I don't understand whats going on, anybody elsee hear anything?