A 1999 Document, "Warning to the Polish Nation" by a Polish half-Jew who met Katyn murderers in Israel presents the 1940 massacre of 14,000 members of the Polish elite in 1940 as revenge for abandoning Poland and its Jews to Hitler. This might shed light on Katyn II, the April 2010, Smolensk plane crash that killed President Kascinski and 95 Polish leaders. As far as we know, no Jews died. The Chief Rabbi of Poland was invited but did not attend, citing the Sabbath.
I was reading the above website and would be interested to hear other people's thoughts on this.
I should've added I mean the section concerning the Katyn Massacre etc