Who killed the Polish President?

The responses on the BBC website shows a large proportion of Polish paranoia and accusations aimed at the Russians, of whom many Poles are less than fond of.

However, the dead President, whilst being very conservative on social issues, was resistant to pushes for an uncontrolled free market economy.  And his central bank chief was also on the plane and amongst the dead.
The Wall Street Journal Market Watch reports that stocks in Warsaw actually rose on Monday.
The CIA has performed numerous black ops in the past on behalf the mafia-type hoons that control the U.S. government.

However, suspicions of it being the Russians, the CIA, or even the Polish pro-business Prime Minister's  political masters or cronies, are just that and may never be proven to be otherwise.

Perhaps, after all, it was just a terrible accident......