David Pecaut, one of Toronto's biggest civic boosters and a co-founder of the Luminato arts festival, has died from colorectal cancer.

The 54-year-old was a tireless organizer whose goal was to make Canada's biggest city a vibrant place for all its residents.

Working on projects that ranged from the City Summit Alliance to the Toronto Region Immigrant Employment Council and then Luminato, Pecaut was a beacon in the city's civic life.

American-born businessman and Luminato co-founder David Pecaut has been hailed as a visionary and a tireless promoter of his adopted hometown, Toronto. (Toronto City Summit Alliance)

"David was a man of boundless energy and optimism, who freely gave of himself to improve the city he loved," Ontario Premier Dalton McGuinty said in a release.

"I will remember him for his passion for people, his courage and his idealism. I will miss his exciting ideas and, above all, his warm friendship."

While fighting cancer, Pecaut took on another challenge — fundraising for the Toronto International Film Festival's new home, Bell Lightbox. A few months into his latest volunteer work, Pecaut was forced to quit because of his deteriorating condition.

"His reach was expansive, his energy boundless and infectious. We were so fortunate to have benefited from his longstanding and passionate support of TIFF," festival director Piers Handling said in a statement Monday.

"We will miss his creative leadership and fearlessness in trying to build a better community for everyone."

The Sioux City, Iowa-born Harvard graduate, who also received a master's in philosophy from the University of Sussex in Britain, arrived in Toronto in the 1980s and became one of its leading visionaries.

Pecaut worked as a senior partner with the Boston Consulting Group, a management consulting company, but worked pro bono for all of his Toronto organizations. He was also the chief executive of venture capital firm iFormation Group when he died.

A Renaissance man

He married Ontario Liberal insider Helen Burstyn in 1990. Burstyn already had two children and the couple added two more girls to their family.

"The reason I found him so interesting was that he was a Renaissance man as well, who could talk about literature and theatre," Burstyn told the Toronto Star.

'It was impossible to say 'no' to him because he worked miracles to find common ground where the only answer was 'yes.'—Toronto Mayor David Miller

From the 1990s onward, Pecaut would sit on boards or help create several municipal organizations including the Toronto Region Research Alliance, the Strong Neighbourhoods Task Force, Career Edge, as well as the Prime Minister's External Advisory Committee on Cities and Communities.

"David was a rare breed of city-builder. While American by birth, his heart and passion belonged to Toronto," Mayor David Miller said in a statement.

"It was impossible to say 'no' to him because he worked miracles to find common ground where the only answer was 'yes,' said Miller.

One of Pecaut's biggest jewels in his civic crown is the June Luminato arts and culture festival, which he launched with businessman Tony Gagliano. The festival showcases top Canadian and international talent.

The pair managed to make it a marquee event with more than one million visitors in just three years.

Went to chemotherapy while attending Luminato events

Pecaut revealed in June that he was battling cancer. While undergoing chemotherapy, he still managed to get out and shake hands during the 10-day event.

"I have to pace myself, so I try to pick my spots. And Luminato was so special for me this year, because every day I could get to one or two things that meant a ton to me, and I felt it was an incredible high the whole time," he said at the time.

After the festival, he told CBC News that Toronto was on its way to being a good role model for the world.

"When, you know, thoughtful people work together in an honest and passionate way, I think incredible things are possible. I think Toronto's best years are still ahead of it. What Luminato … represents is still just a fraction of the potential of what this city is going to achieve in the next 50 or 100 years."