When you hit rock bottom, the only way to go is up. In “La Brea,” they take that literally.

The NBC drama, which airs Tuesdays, splits its time between two worlds. The first: Los Angeles, where a massive sinkhole opened up near the La Brea Tar Pits, pulling parents, children, teachers and co-workers into the sucking void and leaving their loved ones behind.

The second: The bottom of said sinkhole, a primeval land surrounded by strangers with no idea what lies beyond their grassy clearing.

“It’s ‘Lost’ meets ‘Stranger Things,’” Jack Martin, who stars as Josh Harris, a high school student pulled into the sinkhole with his mother, Eve (Natalie Zea), said.

“Lost,” at best, seems to be a guiding light for “La Brea,” trying to re-create the magic of ABC’s hit series about a crowd of misfits whose plane crashes onto an ocean in the South Pacific. But the showrunners stressed that they want to focus more on the characters than the sci-fi nature of their new world.

“The story is about trying to get home and trying to reconnect with their loved ones,” creator David Appelbaum said. “Who gets home and who reconnects? That’s something the audience is really going to want to know.”

While Josh and Eve are figuring out their new reality down below, along with a former Navy SEAL (Jon Seda), a psychologist (Chike Okonkwo) and dozens of other stragglers, everyone above is trying to cope with what just happened.

“I think when someone falls in a sinkhole, they’re probably dead,” star Zyra Gorecki, who plays Izzy Harris, Eve’s daughter and Josh’s sister, joked.

The viewer knows that’s not true. Izzy’s dad, Gavin (Eoin Macken), may know that’s not true, too, thanks to what he and doctors had written off as hallucinations after he crashed his plane into the desert years ago. Now, those same visions may be the key to finding his son and estranged wife, if only anyone would believe he’s not just crazy.

“He’s trying to justify his craziness to save his family,” Macken, 38, said. “The possibility of something that has defined you as being nuts and actually being suddenly a complete turnaround and being able to use that to save your family ... is such a huge concept to even consider.”

For Gavin, the battle is not just deciphering his hallucinations, but convincing everyone else that he’s right.

Okonkwo, the 39-year-old British actor playing a psychologist trying to keep the peace — or find it — inside the sinkhole, paints a hopeful picture in the center of chaos, one that doesn’t necessarily line up with reality.

“There’s sometimes this ‘Lord of the Flies’-esque idea that we would devolve into wretched society, but when it comes down to it, humans are really good to each other when the chips are down, when things get tough,” he said.

For some down below, that serves to be true. For others, it won’t. And sometimes, it depends on the situation.

“We’re seeing examples of the best and the worst. People make choices,” showrunner Bryan Wynbrandt said.

“What do you do when your family member is injured and you have a choice between helping them and someone else? That’s a moral dilemma that’s really interesting to thrust characters into. We do that. They don’t always make the right decision. They make choices that affect others negatively, even if they’re doing it for the right reason.”

Eve, introduced as a relatively boring officer manager, has a few secrets up her sleeve, Zea teased. But mostly, they survive because they have to.

“We’re able to watch these people take what is arguably the worst day of their lives and to build upon it, to make it something that’s livable and safe and sustainable,” she told The News.

Back in Los Angeles, Izzy and Gavin are fighting to figure out what happened. Down below, the survivors are fighting to stay alive.

“This show strips everything away and forces us to go to that square one environment,” Martin said.

“Who are you? Who are we really? So often we get to obfuscate that in real life. This situation makes that impossible. We get to see people as they really are. Who am I really? What would I do in a situation like this? If all of this was stripped away, who would I be?”