NEW ORLEANS (AP) — A shingle-for-shingle re-creation of a Katrina-ravaged slice of the Lower 9th Ward went up with a bang recently, bringing an explosive end to a spookily authentic replica of storm devastation.

As realistic as it looked, the scene was all just a bit of movie magic, conjured — and then destroyed — as part of the thriller ‘‘Black Water Transit,’’ starring Laurence Fishburne, Brittany Snow and Karl Urban.

The movie is expected to wrap this month after filming in New Orleans for several weeks.

The star of the set was a decaying yellow one-story structure, seemingly sitting atop another house, all of which the film’s crew built from scratch. And as it turns out, construction of a broken-down building is more of an exact science than one might think.

‘‘When you’re putting a house like this together, you’re thinking structure — it has to stand, you have to be able to shoot inside of it, you have to be able to put crew in there — so you have to be engineering-conscious,’’ said Justin Dragonas, the film’s production designer.

So even though the house looked from the outside as if it were on the brink of toppling over, it was built with a number of hidden safeguards, including a sturdy 1 1/2-inch-thick plywood floor, as well as Plexiglas windows, to avoid spraying shards of glass all over the cast and crew during the scene’s big bang.

There is also what appears to be a utility wire passing through the house, courtesy of an apparent toppled utility pole. In actuality, that wire was a camouflaged structural cable helping to hold the whole thing up.

Dragonas wouldn’t say exactly what fictional events cause the house to blow up. (‘‘I don’t want to give anything away,’’ he said.) But when local movie-goers watch the Tony Kaye-directed film, set for release next year, they can watch for the scene in which Urban, playing a character named Earl Pike, walks out of the house, turns around and fires a gun into it.

The result is a spectacular orange fireball, with the New Orleans night as a backdrop.

But long before cameras rolled, and before crews even put hammer to nail, they spent a good amount of time studying post-storm photographs in order to replicate authentically the post-K scene.

‘‘Also, there was actually a house down the block that was tilted in the same way — it was a lot smaller, and we obviously couldn’t shoot inside of it — so we used that as a model,’’ Dragonas said.

Building the house was only one part of the scene-setting process, however. Vehicles, including boats and a school bus, were brought in and flipped. Surrounding trees were stripped of many of their leaves; grass and other vegetation was trimmed back. The streets were filled with mud. Things such as satellite dishes and furniture and children’s toys were strewn about.

‘‘Basically, everything you can think that was inside or attached to a house, we had at least one of somewhere,’’ Dragonas said.

The filmmakers also paid nearby property owners to hold off on the demolition of their homes so those ruined structures could offer a realistic background, with a promise that the production company would pay to demolish the houses when they were done shooting.

The set was so realistic, in fact, that it prompted strong emotional reactions from tourists and neighborhood residents, as well as from crew members, some of whom quit the production after realizing that their Katrina-inflicted wounds were still just too raw.

‘‘There were some people who were not happy. Because of the subject matter, it hit a little too close to home — and that’s understandable,’’ Dragonas said. ‘‘I get it; I’m from New York, and when I see ’United 93’ …’’