At the bottom of a dank salt mine in Colombia, a 200-strong film crew featuring Spanish actor Antonio Banderas is reconstructing the incredible tale of 33 miners buried alive for 69 days in Chile in 2010.

Actors from multiple countries work in suffocating heat on "The 33," which traces the unlikely survival of the men trapped deep underground after a collapse at the San Jose copper mine in the Atacama desert.

"It's not just about the physical ordeal these 33 men went through -- it's about the emotional one, of wondering if they would live or die, or if they would go crazy waiting to find out," Gregg Brilliant, a spokesman for the American film production, told AFP.

To depict the incredible story that unfolded more than 600 meters (1,970 feet) underground, the production team chose to film at two sites outside the Colombian capital Bogota.

Behind a security cordon, curious onlookers try to catch a glimpse of a star, but their Hollywood hopes are repeatedly dashed.

In the salt mines of Nemocon, the humid and musty environment combine with the thin mountain air to recreate the oppressive atmosphere at San Jose, located 800 kilometers (500 miles) north of Chile's capital Santiago.

The film recounts the story of the mine accident and how all 33 men -- 32 Chileans and a Bolivian -- eventually escaped in a spectacular rescue operation watched around the world.

Banderas, 53, will play Mario Sepulveda, the charismatic de facto leader of the group.

French actress Juliette Binoche, who replaced Jennifer Lopez in the cast, and Americans Martin Sheen and James Brolin also star in the film.

Under the guidance of Mexican-born American director Patricia Riggen, the actors sweat profusely, keeping make-up artists hard at work before each take.

"The ambiance is real. You don´t have to act so much," said Lou Diamond Phillips, who plays Luis Urzua, the mining team's shift leader nicknamed "Don Lucho" who organized the men's food supply during their ordeal.

Hard to show weight loss on screen

Producers relied heavily on a vast trove of data about the incident, including the miners' medical reports, to make the film as authentic as possible.

Depicting the weight loss of the miners, who survived on tins of tuna and small sips of milk, proved a major obstacle.

Head of makeup Ana Lozano said that recreating the miners' emaciated look was her most complicated task. Despite dieting, none of the actors were able to lose as much weight as the men they portrayed.

The film crew played with light and shadow effects to mark the outline of the miners' ribs and experimented with small prosthetic devices to accentuate their eyes.

Latex was used to simulate the redness and peeling of their skin.

After filming wraps in Colombia, the team will head in early 2014 to the Atacama desert, Brilliant said.

Binoche will make her debut on set in the desert as Dario Segovia's sister, who organized a makeshift village near the mine where family and media gathered to await news of the miners.

"The film isn't just about the event itself -- it's about the people, both above and below ground, who held onto their love and their hope to pull them through what seemed like an impossible rescue," said Brilliant.

The movie however will not recount the story's real-life ending, which is less joyous.

The men's fame neither lasted nor brought them the fortune for which they had once hoped.

"We are like a big family -- but with each going his own way," Urzua, the real "Don Lucho", told AFP from Chile. -- AFP