At the Hot Docs premiere of Air India 182, the audience was a study in collective catharsis. Filling all 992 seats of the Winter Garden Theatre, moviegoers watched in horror as a flight from Montreal to New Delhi exploded over the Atlantic Ocean. For many of them, the film was a dramatic history lesson, but for the close friends and family of the Air India victims who sat in the audience that first night, the tragic narrative was all too familiar. It’s the wrenching remembrances of family members that form the emotional core of the documentary. Their descriptions of seeing loved ones off at the airport for the last time are almost too painful to watch. “I found it excruciating,” says Sturla Gunnarsson, the film’s director, of the premiere. “It was the most difficult screening I have ever been to.”

For almost a quarter century, the Air India bombing has floated on the edges of our country’s consciousness. Most Canadians don’t know who was responsible or whether anyone was ever arrested for the crime. Wasn’t there an inquiry? Or something? And perhaps we shouldn’t be blamed for our blind spot. On the day of the worst mass murder in Canadian history, then–prime minister Brian Mulroney telephoned the prime minister of India to express his condolences, seemingly ignorant of the fact that 280 of the 329 people on board were Canadian citizens. Our own leader didn’t consider it an incident of national relevance, so it’s not surprising that we haven’t, either.

“If those people had been blond-haired and blue-eyed, the bombing would have transformed Canadian society,” says Gunnarsson, who himself is very blue-eyed, not to mention tall and broad-shouldered and generally Nordic in appearance. Born in Iceland in 1951, he was seven when his family immigrated to Vancouver, which has had a strong Sikh presence for more than a century. In the mid-1970s, he attended film school at UBC and met his future wife, Judy Koonar, also a film student, whose Sikh grandfather had moved to B.C. in 1903. Having attended temple with his wife’s family, Gunnarsson knew of the friction between the old guard of moderate Sikhs and a more militant group of newer immigrants. For the couple, the 1985 bombing was devastating, but not entirely surprising, given the political climate. Still, they were shocked and angry when our government labelled the incident an Indian problem, and frustrated by later revelations that something could have been done to prevent it. Leading up to the tragedy, both CSIS and the RCMP had wiretaps on the alleged terrorists’ phone lines, but the investigation was not a high priority. In the two decades since, all but one of the men responsible have slipped through the cracks of bureaucratic vagary.

Despite his ongoing interest, Gunnarsson refused several offers to turn the story into a fictionalized drama. Without precise details of the bomb’s planning and execution, he didn’t have a complete narrative. “It was a mountain of information with no clarity,” he says. In recent years, most of the CSIS and RCMP wiretaps and interviews were declassified, which meant he could finally tell the story in documentary form. He filmed Air India 182 in less than a year, with Koonar working as associate producer. “The story is close to the heart of our relationship,” he says. “We have a cross-cultural marriage that appreciates Icelandic and Punjabi traditions but is deeply secular.” This distance from ancestral identity defines the Annex-dwelling family: Koonar has referred to herself as an “unhyphenated Canadian,” while Gunnarsson grows impatient when asked if his kids are Sikh. “They haven’t been raised in a religious tradition,” he says. “They’ve been exposed to the Bible and the Guru Granth Sahib, but as cultural texts.”

He’s been nominated for an Oscar (for his doc After the Axe) and has won an Emmy, two Geminis and a Genie. He has five awards from the Directors Guild of Canada, which represents 3,800 industry players. In May, the guild elected him president, which brings a new opportunity to spread his personal brand of patriotism.

On June 22, Air India 182 will air on CBC to mark the 23rd anniversary of the bombing. And as the chance of a satisfying political or legal response grows ever more unlikely, Gunnarsson’s film—methodical, informative and heartbreaking—is the version of the tragedy that will become permanent Canadian history. At last.