Jack Layton's wife, Olivia Chow, stood by his casket for hours Wednesday, comforting friends and fellow members of the New Democratic Party who passed by to mourn the late NDP leader.

Once Canadian dignitaries, cabinet ministers, MPs, diplomats and top NDP staff had made their way through the House of Commons foyer, Chow went outside to acknowledge some of the crowd of hundreds who were lined up to say goodbye to a man many had likely never met.

NDP MPs positioned themselves throughout the public line, which snaked over to the next building and around it, thanking people for coming and chatting with them. Toronto MP Andrew Cash and Timmins MP Charlie Angus were among them.

Chow, NDP MP for the Toronto riding of Trinity-Spadina, went out briefly once, then a second time later in the afternoon, to mingle with the crowd in line.

One woman, Carilyne Hebert, 23, broke down in tears as she spoke to Chow.

"There is a cycle of grief," Chow told the woman. She provided comfort to several of them as they shed their tears openly, she told them to carry on her husband's spirit.

Paul Aubin, standing next to Hebert, also broke down in tears and later said he was honoured Chow came to them.

"She was so serene. The dignity she was carrying is beyond words," Aubin, from Cornwall Ont., said. "I thanked her for the dream Jack instilled in me. We told each other, 'Dream no little dream.'"

"He was a hero," Aubin said, breaking down in tears again as he recounted his exchange with Chow.

After mingling with the crowd for several minutes, Chow gave the crowd a wave, they applauded her and she got in her car. It pulled away as the bell on the Peace Tower rang.

Heritage Canada officials said that as of 7 p.m. ET more than 3,000 people had passed through the foyer to pay their respects. CBC reporters on Parliament Hill said it seemed likely that at least another 2,000 people would pass through before midnight. At 9:30, there were still people of all ages in the line, including children as young as five.

Casket draped in flag

A hearse carrying Layton's flag-draped casket had arrived at Parliament, his home away from home, shortly after 10:30 a.m. ET, pulling up in front of the Peace Tower. RCMP officers carried it into the foyer of the House of Commons, followed by Chow; Layton's children, Michael and Sarah; his beloved granddaughter Beatrice; and other relatives.

The casket was placed in front of the open doors of the chamber of the House of Commons. Inside, a bouquet of white flowers rested atop the desk where Layton sat as leader of the Official Opposition.

After a few private moments, the family, including Layton's first wife, Sally Roy, began the visitation shortly after 11 a.m. Chow approached the casket alone and spent a quiet moment before moving to the side of the foyer, close to a black-and-white photo of her husband that is on display.

Gov. Gen. David Johnston and his wife, Sharon, began the procession of dignitaries. Johnston placed a hand on the casket and gave it a pat, then paid his condolences to Chow and the members of Layton's family standing beside her.

Former governor general Michaëlle Jean and her husband, Jean-Daniel Lafond, were also there, followed by Prime Minister Stephen Harper's wife, Laureen, who wiped away tears as she spoke to Chow and Layton's family. Harper is currently on a trip in the Arctic.

Many of the NDP MPs were emotional as they approached Chow and Layton's children.

B.C. NDP MP Nathan Cullen, wearing a bright orange tie, touched his head to the casket and cried. Chow wiped tears from the face of Ontario MP Rathika Sitsabaiesan, wearing a black dress and an orange sweater.

Long-time Layton press secretary Karl Bélanger spent a few moments at the casket, then touched his BlackBerry to it before moving to the receiving line to hug Chow. The move recalled the way Bélanger would have Layton wrap up his speeches: three messages to make Layton's smartphone vibrate would indicate it was time to go.

Speaking before the visitation, Bélanger said Layton was a bright light for Canadians because of his optimism.

"We feel great sadness at the loss of a great Canadian," he said. "But we also feel the joy, and our hearts are warmed up by the response from Canadians and the messages of support and sympathy that are coming from all across the country, from all political stripes, from all levels. It's very, very touching."

'Build on his legacy'

Former NDP leader Ed Broadbent, who backed Layton to head the party, said MPs are sad now but recognize they have to build.

"We have to build on his legacy and that means to restore ourselves quickly as a political force for the good in Canada," Broadbent said. "And I have a lot of confidence because of the enthusiasm of this caucus and the party that that will be done.

"It's his mandate. He brought them here, he led them here. And not for a vague notion. For real social change, for the benefits of ordinary people, and they are determined to continue with this mandate."

Speaking with reporters Tuesday, Harper recalled many memories of Layton, including the exchange of phone calls every Christmas. He described his last meeting with the Official Opposition leader at the end of the session when they were locked in a "Parliamentary battle." He said it was obvious to him then that Layton was far more ill than he was before the May 2 election.

"But even at that moment, with the big personal challenge he had in front of him and with the big battle we had going on between us, he was just still full of optimism and good will, and that's what I'll remember," Harper said.

Industry Minister Christian Paradis arrived with Laureen Harper, representing the government.

A steady stream of friends and colleagues followed, paying respects at the casket, speaking to Layton's family and signing a book of condolence.

The NDP's two deputy leaders, Thomas Mulcair and Libby Davies, approached the casket together. NDP interim leader Nycole Turmel was also there.

Sixty-five NDP MPs and a number of MPs from other parties were on Parliament Hill for the lying-in-state, including interim Liberal leader Bob Rae, Conservative MP and House of Commons Speaker Andrew Scheer and a number of diplomats.

Tributes across Canada

The Quebec Assembly announced Wednesday it would lower its flag to half-mast for Layton's funeral in Toronto Saturday. The Saskatchewan legislature will lower its flags from Wednesday until Saturday.

The CN Tower will be lit up in orange Saturday in Layton's honour.

The memorials and tributes beside the Centennial Flame on the lawn of Parliament Hill continued to grow Wednesday. People continue to stream by to take photos and to add to the collection of flowers, notes and other tributes.

The lawn was freshly cut Wednesday morning and crews began setting up the red carpet under the Peace Tower, where the flag is flying at half-mast, early in the morning.

After dignitaries and the public pay their respects in Ottawa, Layton will lie in state Friday and Saturday in Toronto's City Hall, another place he spent much of his time before his career in federal politics. A state funeral for Layton will be held Saturday.

Parliament's Centre Block, normally full of tourists in the summer, was closed for the morning. The visitation for the public was scheduled to begin at 12:30 p.m. but began late because so many dignitaries arrived to pay their respects.

Some of the NDP MPs have travelled from around the world to be in Ottawa, cutting short their vacations. NDP MP Niki Ashton was on her honeymoon in Greece.

Flowers for the late NDP Leader Jack Layton were on his desk in the House of Commons on Wednesday, as he lay in state in the foyer. (CBC) A departure guard and a 15-gun salute will end the Ottawa portion of the memorial Thursday. The carillon will play O Canada before the casket leaves for Toronto.

Lying-in-state is a tradition where the remains of the deceased rest on view, with a vigil, according to the Department of Canadian Heritage. Four constables from the House of Commons guard will be positioned around the casket.

Layton's funeral is set for 2 p.m. Saturday in Toronto at Roy Thomson Hall, which holds 2,500 people. Officials are making plans to accommodate the expected overflow.

Books of condolence

MPs from all parties are hosting open houses throughout the week, offering books of condolence for their constituents to sign at their offices across the country. Those who want to express their sympathies or share stories about Layton but can't make it in person are encouraged to sign a virtual book of condolence on the NDP's website.

The NDP are asking for donations to the Broadbent Institute in memory of Layton in lieu of flowers.

The Broadbent Institute is an NDP-affiliated think tank that was announced at the party's 50th anniversary convention in June.

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