Phone alerts and cognitive framing: recent events

Today, I think we're all aware what happened in Boston.

Well, just as I'm coming home and the story is unfolding on the TV, the phone rings with an automated message saying "Political Alert". Over the last year, I've noticed more and more "red cross" icons popping up on my cell phone's notifications tray. Many times they are weather related, though other times its some event deemed important (such as the recent Amber alert for the two boys in Tampa).

My question is this, why would today's events be placed in the category of "political alert". Why not "emergency alert"? What makes these events political by definition?

I'm legitimately asking your opinions.

How, specifically, does this unfolding series of events merit the label "Political Alert"?

And, in what way does the quality of "emergency" status of these events get trumped by the political status given by the broadcast?

Can we hazard a guess as to the potential mass framing of the events of today; how that framing leads to a generally accepted narrative that will be given? In other words, now having identified these events as a "political alert" as a society, are we now more apt to want or expect to see further developments regarding these events couched in political discussion - as opposed to, say, public safety discussions or war-related discussions?