Man severely injured in explosion in New York's Central Park

Sounds like it was someone trying to set off a homemade fireworks rather than anything to do with terrorism international or national.
http://www.npr.org/sections/thetwo-...rist-injured-when-explosive-material-goes-off
[rquoter]The FBI, along with the NYPD, are looking into the incident which they believe was a fireworks experiment.

"It is not unusual for the public to make or try to create homemade fireworks around the Fourth of July," John O'Connell, a deputy police chief for counterterrorism with the NYPD, told Times.[/rquoter]

 

Whether this was or was not related to terrorism does point out one thing. It is very difficult to make a functional bomb and usually very dangerous to the bomb makers themselves.