WIKIPEDIA:
The Smolensk air disaster occurred on 10 April 2010, when a Tupolev Tu154 aircraft of the Polish Air Force crashed near the Russian city of Smolensk, killing all 96 people on board. Among the victims were the President of Poland Lech Kaczyński and his wife Maria, the former President of Poland in exile Ryszard Kaczorowski, the chief of the Polish General Staff and other senior Polish military officers, the president of the National Bank of Poland, Polish Government officials, 18 members of the Polish Parliament, senior members of the Polish clergy and relatives of victims of the Katyn massacre. The group was arriving from Warsaw to attend an event commemorating the 70th anniversary of the massacre, which took place not far from Smolensk.
The pilots were attempting to land at Smolensk North Airport—a former military airbase—in thick fog, with visibility reduced to about 500 metres (1,600 ft). The aircraft descended far below the normal approach path until it struck trees, rolled inverted and crashed into the ground, coming to rest in a wooded area a short distance from the runway.