True Crime: The real life horror story that inspired 'I, Tonya'.

It was the beginning of 1994 and Nancy Kerrigan was the most popular figure skater in the United States.

She was America’s sweetheart on the ice, the public loved her and advertisers couldn’t give her enough of their money.

But Kerrigan’s illustrious career was about to come under threat.

On the evening of January 6, 1994, Kerrigan and her rival on the ice, Tonya Harding, had just squeezed in one more practice before the US Women’s Championships the next day.

The competition would determine who would represent America in the Winter Olympic Games that year.

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As Kerrigan was preparing to leave Cobo Arena ice rink she was viciously assaulted by a stranger. The unknown man, who was wearing at black hood at the time of the attack, targeted the kneecap on her landing leg.

The world looked on in horror as the moments before and after the attack were caught on camera. An hysterical Kerrigan was filmed lying on the ground, screaming and crying, and asking ‘Why?’ over and over again.

Luckily, the assailant didn’t break any bones. Kerrigan was left bruised and swollen and she had a severe limp, which meant she wasn’t able to compete in the Championships the next day.

However, her fellow skaters agreed that she deserved the one of the two spots on the 1994 Olympics team despite her injuries.

Harding went on to win the other spot through the competition.

But before the two rivals could compete at the Olympics, it was revealed that Harding was behind the attack on Kerrigan.

Harding’s ex-husband, Jeff Gillooly, was charged with hiring a hitman and Harding was found guilty of conspiracy after the fact.

After denying any knowledge of the incident, Harding eventually admitted she found out about the attack after it occurred and failed to take any action.

Gillooly and the two other men sentenced for the crime always claimed that Harding had knowledge of the attack before it happened.

The brutal attack on Kerrigan was planned and it was aimed at crippling Kerrigan and ruining her chances of making it onto the Olympic team.

You see, Harding and Kerrigan had been locked in a fierce competition for years.

In 1991, Harding became the first American woman to land the rare triple axel, earning her a perfect score and first place at the US Figure Skating Championships, while Kerrigan came in third.

Harding always had a competitive edge over her rival but the public just adored Kerrigan. Her good looks and charming personality meant the media couldn't get enough of her and she scored huge sponsorship deals with brands like Revlon, Reebok and Campbell's.

While Kerrigan was often dressed in Vera Wang on the ice, Harding wore outfits she'd handmade herself.

It was this toxic rivalry, that had been bubbling under the surface for years, that led Harding to commit such an unthinkable crime.

The US Olympic Committee tried to disqualify Harding from the competition in Lillehammer, Norway, but when she threatened them with a $US25 million lawsuit they had no choice but to let her compete.

This led to one of the most awkward moments in Olympic history. Kerrigan was forced to share the ice with Harding during their practice and both figure skaters actively ignored each other.

In a very deliberate move, Kerrigan wore the same white lace dress she was wearing when she was attacked.

The women's figure skating event from that year's Olympics remains one of the most-watched events in sports history.

Kerrigan, boosted by the public's support, went on to have the best skate of her career and she took home the silver medal.

Harding, on the other hand, had an absolute shocker.

She failed to land her first jump, then cried and begged for a second attempt. She ended up coming in eighth place.

The 1994 Olympics was the last time both Kerrigan and Harding skated professionally.

Kerrigan would go on to have an impressive career in the media, hosting Saturday Night Live, writing a book, and appearing in Will Ferrell's 2007 comedy Blades of Glory.

Harding, on the other hand, had a very different life.

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The former professional skater tried her hand at acting, music, wrestling and boxing but nothing really stuck.

In the mid-90s, she and Gillooly sold a sex tape they’d filmed on their wedding night. Harding was also arrested twice - once for DUI and once for suspected domestic violence against her then-boyfriend.

In 2008, she released a memoir called The Tonya Tapes in which she admitted feeling some guilt over the crime.

“Of course I feel guilty for what happened,” Harding said. “But I can’t dwell. I have to go on living.”

The epic rivalry between Harding and Kerrigan, which led to such a insidious crime, is now the focus of a major Hollywood blockbuster called I, Tonya.

The film starring Margot Robbie and Caitlin Carver will be in cinemas in January.

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