Russian investigators suggest human error may be to blame for Saturday's crash. They say there were no technical problems with the soviet-made jet.
In Warsaw, people are stopping by the presidential palace to pay their respects. Poland's acting president says he'll call for early elections within the next 14 days with the vote being held within another 60 days.
In Chicago -- students at the University of Illinois at Chicago organized a memorial on their campus to pay tribute to those who died in the plane crash, including a Chicago artist.
Wojciech Seweryn helped create a monument in Niles for the victims of the Katyn Massacre. The Polish delegation was on its way to observe the anniversary of that massacre when their plane crashed. Seweryn's body has not been found. His relatives have reportedly provided a DNA sample to help identify his body when it's found.
The Polish Consulate in Chicago is allowing people to express their condolences to the families of the crash victims. They've provided visitors with a book that they can sign at their office on Lake Shore Drive. Cardinal Francis George, Senator Dick Durbin and many other Chicago leaders have signed it.
