Polish President Lech Kaczynski, Wife Lie in State

President Obama plans to attend funeral set for Saturday.

WARSAW, Poland, April 13, 2010— -- The flag-draped coffins of Polish President Lech Kaczynski and his wife Maria were placed side by side in Warsaw's presidential palace today and the gates opened so Poles could come pay their final respects.

Mourners filed past, kneeling at the coffins. One of the most poignant images of the day was first daughter Marta visiting her parents as they lay in state.

The images were displayed on large screens on the street in front of the palace where thousands more either stood in silence or headed to the back of the line into the palace that stretched as far as the eye could see.

A sea of candles and flowers was tended to by scout troops. They waded through, collecting the dead flowers and extinguished candles that left wax all over the street.

Maria Kaczynska's body arrived back in Warsaw this morning, two days after her husband's. She had been one of the many unidentified bodies of Saturday's crash that killed 96, identified Monday thanks to her engraved wedding ring.

Her coffin was met at the airport by her daughter and the president's twin brother Jaroslaw, before making its way to the palace as throngs on the side of the road threw flowers at the hearse.

The plane crash Saturday in western Russia killed 96 people, most from a presidential delegation that included many of the country's top political, military and religious leaders.

"I've never ever seen something like this in my life," said Polish journalist Piotr Krasko. "I was covering a lot of horrific events like Katrina, 9/11 in the U.S. ... But for the very first time in my life, it's happening to my nation, my people, my president."

A large red screen read "Katyn 2010," echoing the tragic irony noted by many in the crowd that the delegation of political and military elite was on its way to attend a ceremony commemorating 22,000 Polish officers murdered by the Soviets that very day 70 years ago.

"It's very, very difficult to talk about it at this stage because we are still in a very big shock," said Beata Kozlowska, a woman in the crowd outside the presidential palace.

Investigators are still examining the voice and data recorders recovered from the plane's black boxes. They have said the recordings rule out technical failure and argue that the pilot of the plane ignored repeated calls to divert the plane to another airport because of dense fog.

A third black box with equipment data was found today and is coming to Warsaw for examination.

"Now we need to synchronize them to have a full picture what happened with the flight," Polish military investigator Zbigniew Rzepa told ABC News, adding that results would likely be released Wednesday or Thursday.

There has been rampant speculation that the pilot may have been pressured to land in order to avoid delaying the ceremony of the Katyn massacre, one of the most painful moments in Polish history.

In 2008, Kaczynski used his commander-in-chief title to try and pull rank over his air force pilot, ordering him to land in Georgia while the former soviet republic was at war with Russia. The pilot refused, landing instead in Azerbaijan. Kaczynski was furious, according to reports at the time, threatening to have the pilot demoted.

Poland's prime minister intervened and the pilot was later awarded a medal for his decision.

On Saturday, the 36-year-old Polish pilot circled the runway twice before making the fatal approach. The Smolensk air traffic controller told a Russian news site that the Polish crew spoke poor Russian, that they had trouble giving their altitude. The international language of aviation is English.

"Conversations were in Russian, English but also in Polish," Rzepa said.

Kaczynski and his wife will lie in state until this weekend, when their funerals will be held at Krakow's famous Wawel Cathedral. President Barack Obama said Tuesday that he would be attending.