Arnold Schwarzenegger Is a Father Driven by Grief to Kill in New Film 'Aftermath' : Inside the Tragic Real-Life Story

Arnold Schwarzenegger's new film explores how the dark depths of grief can drive a man to do the unspeakable.

In the new drama Aftermath, Schwarzenegger takes on the role of Roman, a character loosely based on the real-life Vitaly Kaloyev — a Russian man convicted of murdering the man who he believed was responsible for the tragic plane crash that killed his wife and two kids.

"It's the most impossible situation," director Elliott Lester tells PEOPLE. "No one is winning. It's the most awful thing that could possibly happen."

So what drove Kayoyev to murder? Here's an inside look at the real story that inspired Aftermath.

Like many people standing inside a Barcelona airport on July 1, 2002, Kaloyev was anxiously awaiting the arrival of his wife, Svetlana, and two kids — son Konstantin and daughter Diana — from Moscow after spending nearly a year apart. (Kaloyev, a respected architect at the time, had been in Barcelona while building a house for a wealthy client.)

But their flight never landed.

While flying over Germany, Bashkirian Airlines Flight 2937 collided with a cargo airliner — DHL Flight 611, which was traveling from Italy to Belgium. The DHL plane had only two people on board, but Flight 2973 was full — 45 children, 15 adults and nine crew members. All 71 people — including Kayolev's family — aboard both planes were killed in the crash.

Kayolev was among the first relatives to arrive at the crash site, and he immediately began searching for their bodies, reports Newswire.

While he managed to find his daughter Diana, Svetlana had landed in a corn field and his son on the road in front of a bus shelter — both having fallen 36,000 feet.

"As a father, your sympathy is with Vitaly," says Lester. "Here's a man who just lost his entire family. I can't imagine what that would be like — not to be able to say goodbye or have a last memory."

An official investigation by the German Federal Bureau of Aircraft Accident Investigation found that a number of shortcomings on the part of the Swiss air-traffic-control service in charge of the sector involved were the primary cause of the collision, along with ambiguities in the procedures regarding the use of TCAS, the onboard aircraft collision avoidance system.

Following the investigation, air-traffic controller Peter Nielsen was cleared of charges of negligence, according to Newswire. Though he was still employed by the company, he eventually decided to retire.

Devastated by the loss of his family and unhappy with the results of the investigation, Kayolev reportedly suffered a nervous breakdown.

"Vitaly is trying to rationalize it," says Lester. "But it was an accident, so you can't."

"There's no one to blame in this," adds Lester.

Kaloyev was offered a settlement of 160,000 Swiss Francs in exchange for not pursuing the company, Skyguide, criminally.

His grief slowly turned into rage.

"There were no moments of light for Vitaly, and there are no moments of light in the film either," says Lester. "There's no hope. When you lose absolutely everything, I don't know how you come out of that level of grief."

"I have been living at the cemetery for almost two years, sitting behind their graves," said Kayolev, according to Newswire.

Furious that the company put a dollar amount on his loss, Kaloyev asked to meet with Nielsen face-to-face — a request that was continually ignored. Overcome with a sense of injustice, he hired a private investigator who helped him track down the air-traffic controller's address.

Two years after the crash, Kayolev turned up at Nielsen's doorstep in Switzerland and stabbed him to death. Nielson died in the arms of his wife and children.

"Vitaly says he doesn't actually remember [committing the murder]," explains Lester. "He was so overcome with grief. It was a crime of passion."

"Killing him didn't make me feel any better," Kayolev later told the Russian daily Moskovsky Komsomolets.

Kayolev was sentenced to eight years in prison but served only three years. He was released after Russian officials pressured Swiss authorities and Kayolev insisted he was mentally unstable.

"The film shows an aspect of grief and opportunity for forgiveness," says Lester. "At some point, you can make sense of the worst, tragic of circumstances and ultimately find that piece of forgiveness. It's about the capacity of being a human being."

Aftermath is in theaters now.