It was all supposed to be “utopian.”

High-rise apartment towers, surrounded by trees — and other apartment towers — would provide affordable housing, convenience, population density that makes mass transit and other service deliveries “efficient” and could create instant “community.”

It hasn’t exactly worked out that way in much of the world, but maybe South Korea would be different.

That’s the promise of “Concrete Utopia,“something set up and underlined in TV news coverage and documentary footage in the opening sequence of Uhm Tae-hwa’s Oscar submitted thriller.

That’s before the “event,” the “dystopian premise of the film is established.

It came with the roar of a giant beast, giving one the first thought that this would be another South Korean tale of disaster brought on by zombies or toxic-waste created river monsters. But this rumble is from a seismic wave, a building-toppling ripple caused by a catastrophic earthquake.

And this disaster apparently isn’t something localized. For “Concrete Utopia” and its “Lord of the Flies,” “Animal Farm” and “The Omega Man” parable to work, the survivors here — the residents of the last tower standing, Seoul’s Hwang Gung Apartments — government has to disappear. “International aid” is off the table.

With no power, communication, food or water supply, these “216 survivors” in “136 apartments” are on their own.

Confusion and trauma are quickly replaced with how “lucky” and “chosen” they were that they survived, and that they have shelter. It’s winter. But that means other survivors are coming to their doors, begging to get in. They aren’t wholly overrun, but things get crowded and testy pretty quickly.

Nurse Myung-hwa (Park Bo-yong) is instantly welcoming of the desperate mother and little boy who knock at their door. Civil servant/planner husbnd Min-sung (Park Seo-joon) is more wary. He can do the math. With no signs of outside help, not so much as a crackling voice of hope on their walkie talkies, simply surviving medium-to-long term is going to be unsustainable.

Tenants gather to debate what to do, how to organize this impromptu society. Fortysomething mom Geum-ae (Kim Sun-young) called the meeting and asks the right questions through a cacaphony of “They say women are stronger in a crisis,” “outsiders must go” and “We can’t just let them freeze” (in Korean, with English subtitles).

Planner Min-sung notes that somebody has to be in charge, a leader who can organize their survival until help comes or directing people how to restore some of their former life of safety, good health and comfort to them. The group abruptly skips past Geum-ae and Min-Sung as “candidates” and settle on the guy who frantically and bravely put out an apartment fire that could have doomed them all.

Yeong-tak (Lee Byung-hun) seems to have military experience, and the “thousand yard stare”of a man in shock at everything he’s been through on top of what everybody else has been through. And he’s a bit taken aback by this new “delegate” status conferred on him.

But when it’s decided to “throw out” all the “outsiders,” he and Geum-ae formulate an impromptu plan to carry it out, no matter how much Myung-hwa protests. Min-sung and pretty much everybody else just go along.

That’s just beginning of this “human empathy is the first thing to go” disaster parable, as personalities clash, socialism morphs into “You work, you eat” capitalism and impersonal ruthlessness points the picture down a very familiar path.

The plot has a few twists in it, some revealed via flashbacks. The violence, when it comes, is sudden and jolting. The viewer’s loyalties and opinions about what is happening and what should happen are tested. We second-guess decisions and just how much “humanity” any of us would show under this or that set of circumstances.

Uhm’s third feature is also his first parable without a supernatural element, which may explain why this step-up in his game never so much as attempts to transcend its genre. All movies like this are civics lessons about what makes a civil society, and this one — while timely — doesn’t go for the obvious object lessons beyond that “perils of ‘strong man’ rule” allegory.

Not that the world couldn’t stand hearing even that right now.

A myopic, tense dystopian thrillers go, “Concrete Utopia” reels us in, jolts and even shocks us and gets the viewer thinking, at least a little. Not every action film or disaster movie can make that claim.

Rating: unrated, violence

Cast: Lee Byung-hun, Park Bo-yong, Park Seo-joon, Kim Sun-young and Park Ji-hu.

Credits: Directed by Uhm Tae-hwa, scripted by Uhm Tae-hwa, Jo Seul-yeah and Lee Shin-ji, based on the webtoon “Cheerful Neighbors” by Kim Soong-Nyung. A Lotte Entertainment/815 Pictures release.

Running time: 2:10