The bartender, Douglas “Buddy” Rasmussen (right), and his boyfriend Adam Fontenot (left), were regular fixtures at the Upstairs. Patrons described Buddy as a “mother hen” who would always look out for everyone.

On June 24, 1973, a flash fire tore through a gay bar in New Orleans' French Quarter. In less than 20 minutes, 32 people were killed, dozens more critically injured and the ones who managed to escape watched helplessly as friends and lovers burned to death before their eyes. It is believed to be the largest killing of gay people in U.S. history until Sunday, when at least 50 people were shot and killed at an Orlando gay nightclub. Yet politicians and religious leaders were relatively silent. The powerful Catholic Archbishop of New Orleans at the time, Phillip Hannan, did not offer his support or sympathy to victims. And while all signs pointed to arson, the police investigation ran cold. No one has ever been prosecuted.

In this week's magazine , TIME tells the story of the Upstairs Lounge Fire, which remains little known and even less understood despite the epic scale of the tragedy. Events like Stonewall have entered the canon of GLBT history, while other, equally significant moments have lingered in the background. But the movement is still relatively young in the arc of American history and as Harvey Milk once said, “A reading of the Declaration of Independence on the steps of a building is widely covered. The events that started the American Revolution were the meetings in homes, pubs, on street corners.”

As the stories of a survivor who remembers that tragic night, the founder of the church whose local congregation held services in the bar and the lead police investigator on the case show, the Upstairs fire was one such event.

Forty years later, the Catholic Archdiocese of New Orleans apologized for its silence in a statement to TIME: “In retrospect, if we did not release a statement we should have to be in solidarity with the victims and their families,” Archbishop Gregory Aymond said via email on June 17. “The church does not condone violence and hatred. If we did not extend our care and condolences, I deeply apologize.” In a month that anticipates a potentially landmark Supreme Court ruling on gay marriage, the apology is another sign that times are changing.

Click here to read Elizabeth Dias' full story about the fire at the Upstairs Lounge.

