Producers behind the upcoming film Upstairs Inferno on Monday released a new trailer for the documentary and launched a crowd funding campaign to raise funds to finish the film.

In the film already in production, director Robert L. Camina takes a look at the 1973 firebombing of a New Orleans gay bar that left dozens dead.

Forty years ago on June 24, massive panic broke out when the Upstairs Lounge was firebombed. Investigators concluded that the fire, which killed 32, was arson, but no one was ever charged with the crime.

What happened that night and how it set back the gay rights movement in New Orleans is the subject of Upstairs Inferno.

Camina has previously said that “with access to new leads, the film is pursuing untold avenues of the story.”

An Indiegogo campaign to raise $12,500 toward completion of the film was launched Monday. Contributor perks include t-shirts (at the $200 level) and a signed copy of the film's script ($500).

Camina also released a new 2-minute trailer at the campaign's website.

Camina's previous film, Raid of the Rainbow Lounge, documented the 2009 police raid of a Dallas-Forth Worth gay bar which left the local LGBT community stunned.