[mac_truck]

It makes me wonder, however, why the FSB (aka KGB), who knew enough about the Tsarnaevs to warn the FBI prior to the Boston bombing, couldn't see this coming: bombing the train station in Volgograd (aka Stalingrad) has all sorts of symbolic implications, much as bombing the Boston Marathon did in this country.

Its been reported that the bomber blew herself up at a metal detection checkpoint before entering the main part of the terminal, which is why the number of people killed by the blast was so low. Not sure what else the Russian authorities could do to protect the travelling public from this type of asymmetrical threat without making it impossible to get around.

[Bikkuri]

I had read the same thing... she saw the police at the checkpoint/metal detector and got nervous (not sure how they could figure that one out, unless there was CCTV footage)... but it does make sense.