Sydney Flags were flown at half mast. Politicians paid their tributes. Obituaries appeared. A condolence book was brought out. But the final touch was the most poignant - the lights on the scalloped roof of the Sydney Opera House were dimmed to mark his passing. Joern Utzon was not one of Sydney's grandees. He was not a prime minister, a soldier or a sporting hero. He was not even an Australian citizen, but a gifted, if flawed, Danish architect, who left these shores 42 years ago, amid public controversy over budget blowouts and his artistic vision for the Opera House, and never returned to see its completion. Utzon's death at 90 last weekend, at his home outside Copenhagen after a short illness, has generated a heartfelt and often agonised response from Sydneysiders, normally a phlegmatic lot. 'Joern Utzon was a giant among men,' wrote Catherine Reynolds, of Leichhardt, in a letter to The Sydney Morning Herald. 'He gave Sydney an utterly beautiful and unique building that transformed our nation.' The general mood of sadness was no doubt compounded by the recent death of Richard Hickox, 60, the musical director of Opera Australia, the company synonymous with the ethereal building overlooking Sydney Harbour; the iconic roofline has variously been compared to the sails of a yacht, the slices of an orange or a group of copulating turtles. Despite the passage of time, many people still have treasured memories of Utzon, a handsome Dane who brought a touch of cosmopolitan style to staid post-war Sydney. His former secretary, Shirley Colless, calls him a man 'of grace, charm, dignity and humour' who was shabbily treated by the government of the day. Many of the tributes, however, were laced with guilt. Although the Sydney Opera House is now regarded as one of the great buildings of the 20th century - 7.5 million tourists visit the site every year - the city never completely repaired the rift with the Great Dane, who rejected numerous invitations to inspect his masterpiece. Those who knew him in the latter years of his life say Utzon was still haunted by a sense of failure because he had not been able to see the Opera House through to completion, but never felt any bitterness towards Australia. Richard Evans, chief executive of the Opera House, recalls visiting the elderly architect this year. 'We spoke for 40 minutes, and when we left he embraced me and he whispered in my ear, 'No tears', but of course there were,' he said. Towards the end of his life Utzon was showered with every conceivable prize and accolade (even an Order of Australia), yet the Opera House blighted his career. He designed only two other major buildings: the National Assembly in Kuwait city and a church in the Copenhagen suburb of Bagsvaerd. He remained preoccupied with his luminous creation in Sydney. Architecture writer Elizabeth Farrelly calls Utzon 'a tragic hero, Sydney's Prometheus' - a genius who was crushed by a city lacking in the imagination and courage to embrace his vision fully. 'Sydney's craving for glamour shot Utzon to stardom and our addiction to mediocrity brought him crashing down,' she writes. 'Utzon and Sydney put each other on the map, but the intensity of the relationship contained the germ of heartbreak.' Death will not end that strange relationship. In 1999, Utzon was re-engaged by the New South Wales government to draw up a set of design principles for the future development of the famous building. His son Jan, also an architect, has been overseeing the project. The main reception area has been renovated and a western colonnade added, but a proposed A$700 million (HK$3.48 billion) revamp of the Opera Theatre remains in limbo. As the federal government battles the global economic crisis, there are fears that the project could be postponed indefinitely.