Deadly pressure cooker bomb - you can be dead before you hear it

Social and political criticisms

From CNN News | April 22, 2013

Outfront investigators and David Mattingly saw how a pressure cooker bomb works.  The shock wave, blast, and sharpnel goes ahead of the sound of the blast, thus you could be dead before you hear it.

The investigators were in a bunker some 1/4 mile away from the bomb and used nuts instead of nails.  The effect was devastating.  While the blast, very similar to the picture on Boston (with white plume) as only 20 ft across, the shock wave and sharpnel moved farther.

Thus for the first responder they should be wary of the danger posed by the sharpnel right after explosion

The bomb costs less than $100 to make yet is very deadly;  it should not inspire local youth to copy this deadly adventure.  

If you have weak personality, and you to US, then you become  a deadly menace to US society.

I hope Americans do not become xenophobic to migrants (arent they yet?)

Pressure cooker bombs used for years by terrorists? Why was not it detected at Boston?

Social and political criticisms

From Newsmax | by Ted Beamon | April 16, 2013 

The authorities are said to be going over video to ID the bombing suspects at Boston marathon finish line.  (No arrest has been made despite announcements)  The bombers used pressure cooker bombs placed about 100 feet apart and explosions timed at 12 secs apart. The use of the said type of bomb was published in the Al Qaeda Magazine Inspire on line in 2010.  
 
The pressure cooker bomb is most effective, is easy to prepare and escapes detection.  Dog sniffer cant detect pressure cooker bombs.

This may be the reason why despite huge resources of Homeland Security, and being in a steady state of war, the police/security was unable to prevent such bombing