Super/Man: The Christopher Reeve Story first trailer - His children reflect on the heartbreaking loss of an American hero

The first trailer for the highly anticipated documentary Super/Man: The Christopher Reeve Story was released on Monday.

It is a new film that looks at the movie star's 1995 equestrian accident left him paralyzed and how he subsequently used that setback to help others.

Sadly, the American icon died in 2004 at age 52.

Super/Man includes tear-jerking interviews with Reeve's three children Matthew, Alexandra and Will. 

'We said goodbye, he gave this wave,' Reeves' son Matthew recalls in the trailer. 'That was the last time I saw him on his feet.'

There is also commentary from the actor's late wife Dana, who died in 2006 from lung cancer.

And plenty of celebrity friends talk too such as Glenn Close, Whoopi Goldberg, Susan Sarandon and Jeff Daniels.

Super/Man: The Christopher Reeve Story is in select theaters on September 21, with an Encore Presentation on September 25,  which was Reeve's birthday. 

The film, directed by Ian Bonhôte and Peter Ettedgui debuted at the Sundance Film Festival in January.

It left audience members in tears.

The film features home video footage of the star and interviews with his children and actor friends, with fans shown how he rose to fame as one of Hollywood's most beloved stars.

It depicts Reeve's battle with the 'darkest thoughts' after his paralysis - telling his wife Dana: 'Maybe we should let me go; with Dana responding: 'You're still you and I love you.'

He later said: 'When Dana whispered those life-saving words to me... it meant more to me than just a personal declaration of faith and commitment.

'In a sense it was an affirmation that marriage and family stood at the center of everything, and if both were intact, so was your universe.'

One year after his accident Reeve memorably brought stars to tears during his appearance at the Oscars - in which he introduced a powerful film montage recognizing how Hollywood tackled social issues.

In the documentary Glenn Close recounts how Reeve was 'terrified that he could die at any moment' after his accident and how his close friendship with Robin Williams gave his strength.

Close said: 'I've always thought if Chris was still around, then Robin would still be alive.'

His son Will also opens up about losing both his parents within 18 months of one another, saying: 'That was the moment, I've been alone ever since then.'

Will, now a successful sports journalist, was raised by the family's next door neighbors and close friends.

All three children work with the Christopher & Dana Reeve Foundation which aims to cure spinal cord injury by advancing innovative research and improving the quality of life for individuals and families impacted by paralysis.

The foundation's legacy is celebrated in the film, ending with a quote from Reeve on what he believes a hero is.

He said: 'A hero is an ordinary individual who finds the strength to persevere and endure in spite of overwhelming obstacles.'

Reeve notably portrayed the iconic superhero, Superman, in the film Superman (1978), Superman II (1980), Superman III (1983) and Superman IV: The Quest For Peace (1987).

He had also starred in other projects during the course of his career, such as working alongside Jane Seymour in Somewhere In Time (1980).

Seymour told People in March that Christopher was 'an amazing guy.'

She added, 'He was really bright, he was fearless and he loved to be alone. He loved to fly airplanes and sailboats and ride horses.

'He took all his energy and all his intellect and all his visibility to really move the dial and get the stem-cell thing going when nobody wanted to do that. Now it's normal.'