Russia ? Russian investigators suggested human error may have been to blame in the plane crash that killed the Polish president and 95 others, saying Monday there were no technical problems with the Soviet-made plane.

The Tu-154 went down Saturday while trying to land in dense fog near a Smolensk airport in western Russia. All aboard were killed, including President Lech Kaczynski and dozens of Polish political, military and religious leaders.

They had been traveling in the Polish government-owned plane to attend a memorial in the nearby Katyn forest for thousands of Polish military officers executed 70 years ago by Josef Stalin’s secret police.