In an uncharacteristic public outpouring of grief, residents of Toronto took to the streets and created impromptu memorials to the politician, who earlier this year led his socialist-leaning New Democratic Party to official opposition status for the first time in its history.
Outside the Toronto home Layton shared with his wife, NDP Member of Parliament Olivia Chow, mourners left flowers and signed a condolence book on the front porch, the Toronto Star reports. Similar scenes repeated at Layton's constituency office, where tributes were left in his party's trademark orange color.
In Ottawa, the national capital, the Canadian flag over the Peace Tower on Parliament Hill was lowered to half-staff, according to the Ottawa Citizen newspaper.
Layton died at home early Monday surrounded by his wife, children, and other friends and family members.
Just last month he held a news conference where, appearing gaunt and speaking in a raspy voice, he announced he would be stepping down as party leader to fight an undisclosed form of cancer, with the aim of returning to work in September.
Layton was diagnosed with prostate cancer in 2009, but it is still not clear what type of cancer he had most recently battled.
In a letter to Canadians and party members, written by Layton less than 48 hours before his death, he left instructions for his party and expressed his dreams for the country.
"My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we’ll change the world," he wrote in the letter.
Under Layton's eight-year leadership, the New Democratic Party became a national force, building unprecedented support in the French-speaking province of Quebec.
In May elections, the NDP tripled its seats in parliament, finishing second to the ruling Conservative Party and forming the official opposition for the first time in its 50-year history.
Nycole Turmel, a newly elected NDP member of parliament and former head of one of Canada's largest labor unions, stepped in as interim leader.
Layton, in his deathbed letter, suggested that Turmel remain as interim leader until a leadership conference can be held in the new year.