The fire department reported finding a can of lighter fluid at the base of the stairs. The bell for the bar was reportedly rung repeatedly; when the bartender asked a regular patron to open the door and see who was there, flames engulfed the club’s interior. Fire trucks arrived within minutes, but it was too late.

Several bodies were never identified, a fact that some people attribute to families being unable to accept the secret lives that the fire had laid bare. At the time, the governor of Louisiana did not immediately comment on the tragedy, nor did the Roman Catholic Archdiocese of New Orleans. The 32 deaths were front-page news of The Times-Picayune for only two days. Unlike the rallying cry for labor rights after the Triangle Shirtwaist fire or for civil rights after the Birmingham church bombing, Mr. Fieseler points out that “the UpStairs Lounge fire had not been a turning point for homosexual rights in America.” It was quickly and largely forgotten.

Mr. Fein, 50, who calls himself an accidental artist, wanted to change that. He moved to New Orleans in 2005 and enrolled in college, pre-med. A few months later, Hurricane Katrina upended his plans. He needed furniture and, realizing the streets were littered with wood from the flood’s flotsam, he started building wooden signs with imagery screen-printed on top.