Lech Kaczyński, the fourth President of the Republic of Poland, died on 10 April 2010, after a Polish Air Force Tu-154 crashed outside of Smolensk, Russia, killing all 96 aboard. His wife, economist and First Lady Maria Kaczyńska, was also among those killed.
After the death of Kaczyński was announced, a week of mourning was declared by the acting President of Poland, Bronisław Komorowski, spanning 11 to 18 April with a state funeral for the couple held on 18 April. Several countries observed a day of national mourning on the date of the funeral. The couple were buried together in a crypt in the Wawel Cathedral, Kraków, afterwards.
On 10 April 2010, a Polish Air Force Tupolev Tu-154M aircraft crash landed near Smolensk, Russia, killing all 96 passengers and crew. Those killed include Kaczyński, and his wife; the chief of the Polish General Staff and other senior Polish military officers; the president of the National Bank of Poland; Poland's deputy foreign minister; Polish government officials; 12 members of the Polish parliament, including vice-speakers; senior members of the Polish clergy; and relatives of victims of the Katyn massacre. They were en route from Warsaw to attend an event to mark the 70th anniversary of the Katyn massacre. The site of the massacre is approximately 19 kilometres (12 mi) west of Smolensk.