Warsaw, Poland (CNN) -- The body of Poland's first lady, Maria Kaczynska, killed with her husband in an airplane crash in Russia, returned to Warsaw on Tuesday.
Crowds turned out to watch her body being driven to the presidential palace, where the couple will lie in state.
The funeral for the couple will be Saturday in Warsaw, followed by their burial on Sunday in Krakow's Wawel Castle.
President Barack Obama will attend the state funeral, the White House announced Tuesday in a statement. "The president will travel to Krakow to express the depth of our condolences to an important and trusted ally, and our support for the Polish people, on behalf of the American people," the statement said.
The archbishop of Krakow said burying the late president in the historic crypt was the country's way of honoring him.
"I think in this way the Polish nation wants to include him among the greatest and most revered men in Polish history," Stanislaw Dziwisk said on Polish state television.
Men in uniform unloaded the flag-draped casket of Kaczynska from a military plane as a band played Poland's national anthem. Family, friends and Polish officials paid their respects during a brief ceremony.
Kaczynska and her husband were among 96 people killed in the crash.
Under leaden skies broken by sporadic sunshine, mourners took turns bowing their heads in silence before the casket. They included Kaczynska's daughter, Marta, and Jaroslaw Kaczynski, the twin brother of her husband, Lech Kaczynski.
Echoing a similar scene that greeted the repatriation of her husband's body on Sunday, crowds lined the streets and threw flowers onto the hearse bearing the former first lady's casket as it made its way through Warsaw.
Among the mourners, student Kamil Denielewski told CNN the outpouring of public emotion was unprecendented.
"I can't remember anything like that and in fact I have not felt anything like that since now," he said. "It made us united, it made us patriots."
The couple had been traveling with a Polish delegation to Russia for a commemorative service marking the 70th anniversary of the Russian massacre of Polish prisoners of war in the village of Katyn when the plane went down.
Among other Polish officials killed in the crash were Aleksander Szczyglo, the head of the National Security Office; Jerzy Szmajdzinski, the deputy parliament speaker; Andrzej Kremer, the deputy foreign minister; and Gen. Franciszek Gagor, the army chief of staff, according to Kaczynski's Law and Justice Party.
The cause of the crash is being investigated. There have been questions raised over why so many of Poland's military, economic and civic leaders were aboard the same flight.
Aviation officials in Russia, which has emphasized that there is no evidence it was responsible, have said the plane ignored Smolensk air traffic control commands to divert to another airport because of bad weather.
Deputy Prime Minister Sergey Ivanov said Monday that flight recorders were in shape to "conduct a detailed transcript and analysis of all flight information and the work of the plane's equipment systems up till the moment of the crash."
There is also evidence that the crew knew about the poor weather conditions and was advised to land at an alternate airfield, he said.
Poland's ambassador to Moscow, Jerzy Bahr, warned against jumping to conclusions ahead of official inquiries.
"Many people think that this is something which the pilot did wrong, but it must be investigated," he told CNN.
As Poland began a week of mourning, tributes continued to be paid to 60-year-old Lech Kaczynski. A sea of candles continued to grow outside the Presidential Palace in Warsaw Monday as people lined up to sign books of condolence.
Parliament Speaker Bronislaw Komorowski, who is now acting president, has declared "a time for national mourning."
CNN's Geoff Hill contributed to this report.