[SODaniel]

The fire at the JFK Library has just been reported as mechanical and non-suspicious or 'affiliated' with the explosions.

Source: http://www1.whdh.com/video/7newslive/ 7-news live broadcast

Update:

https://twitter.com/BostonGlobe/status/323886879453892609

It was an intentional and controlled detonation of a 'device'.

[pettazz]

Different library. The one the Globe tweet refers to is the Boston Public Library, right by the finish line. The JFK Library is on the opposite side of the city.

[anigbrowl]

Since then the Boston Commissioner of Police has confirmed it as a non-controlled explosion during a press conference.

[rabidonrails]

Bloomberg quoting AP: 2 additional devices found and being dismantled in Boston right now.

(3:24p CST)

[BrianPetro]

> UPDATE: One report was of unexploded device on the glass footbridge over Huntington Ave near Copley place

[BrianPetro]

> RT @ReutersUS: Boston police confirms another explosion at JFK Library #breaking