A MAN is passed out, completely unconscious, on one of the busiest bridges in the world.

He’s been there for a while. To onlookers, it looks like he’s passed out from a drug overdose. He has tyre tracks embedded in his arm; someone has run over him with their motorbike and just kept going. Here, people don’t bother to stop.

For China’s 1.38 billion residents — almost 20 per cent of the entire world’s population — in a country of smog and population density, life can sometimes be grim.

But in this “constantly churning” atmosphere of pollution and traffic, is one legendary bridge.

The Nanjing Yangtze River Bridge carries approximately 80,000 vehicles and 200 trains per day, and has far surpassed San Francisco’s Golden Gate Bridge as the most popular suicide site in the world.

Every weekend since September 19, 2003, Chen Si travels 25km from his home to the bridge. From 7:30am until sun down, he spots the suicidal before they get the chance to take the 70m plunge into the Yangtze River — in some cases dragging them back over the barrier, kicking and screaming, to safety.

But not always.

In an exclusive interview with news.com.au, Chen said that despite the bridge closing for construction last year, that hasn’t stopped the suicides.

Another man is roaming the bridge, he’s shirtless and licking something on the ground. Trouble is afoot.

By the time Chen reaches the man, he’s gone. Disappeared without a trace. There’s no way he could have walked off the bridge without being spotted. Chen is sure he’s just jumped.

Despite saving more than 300 people, it’s the people he can’t save that haunts Chen the most.

He says those with a late-stage disease are the hardest to convince to step off the ledge, as filmmakers Jordan Horowitz and Frank Ferendo, who followed Chen for a year in 2015 for the documentary, Angel of Nanjing, witnessed.

“He said to me on one of the first days, ‘I don’t feel like a hero at all for the people I saved, I feel like a failure for the ones I haven't. That haunts him in some way,” Mr Horowitz tells news.com.au.

“In China, people are very snap decision when it comes to suicide,” Mr Ferendo said.

“When they get upset about something — it’s strange — they forget all logic and don’t think about anything.

“The minute you ask the woman whose husband is cheating on her and she’s trying to commit suicide, ‘who’s going to raise your daughter?’ She’s like, ‘I didn’t think about that’.”

But Mr Si says he’s figured out the four other particular types that come here to bid goodbye; the broken-hearted and the abused among them.

“There was an old man whose wife used to beat him all the time and he came to the bridge to jump,” Mr Horowitz said.

Chen shot to global fame last year when the Angel of Nanjing highlighted the devastating and unrelenting volunteer work undertaken by this unsung hero. At the time, Chen said he’d saved approximately 300 people. In an interview with news.com.au, he said that number had risen to more than 330.

Chen works in IT during the week to support his family and on the weekends, spends his time on the bridge. His monthly salary equates to $A590.57. Outside of his family commitments, he rents a two-bedroom flat where survivors are invited to recover. They receive free psychological counselling from Chen and his university volunteers and are free to stay as long as they please. If not for donations, Mr Si would not have the resources keep his dreams afloat.

“When I talk to those people who want to commit suicide, they are really kind and nice people, they just made a small mistake, took a wrong step,” Chen told news.com.au.

“When we find them and talk to them, we find they are upset, [but in the end] it will be a really good thing for them and their families.

“I can’t be fired by my boss, or else I won’t have the money to complete this mission,” Chen says in the documentary, his brows furrowed.

When China first heard of the man dubbed the Angel of Nanjing, the response was a critical one.

“The way Chen tells it, when he first started doing it there was a lot of media attention from foreign press, and the government didn’t take kindly to that because they thought it was representing China in a bad light,” Mr Horowitz explains.

“A cop came to the bridge one day and said to Chen, ‘if you come back here I’m going to throw you off this bridge’.”

“If you asked a psychologist about what he’s doing he would say his approach is totally wrong. But Chen identifies with the majority of the people that go to this bridge because a lot of them are outsiders, and he feels like an outsider, he migrated to this city for work.

“His approach, he just gets these people, he approaches them as a common guy without any training, and I think that's why he’s so successful, there’s no BS.”

But over the years, Chen’s reputation has developed, so much so that his phone number is now listed in the schoolbook of every Year 8 student in the country. His phone is constantly bombarded with calls. The work, it seems, is relentless.

“My number is still on year 8 student’s book, every year since January to May, they try to call me until my phone is frozen,” Chen told news.com.au.

Mr Horowitz said the grim schedule “took a toll on Chen, it’s clear in the movie.

“He’s aged a lot just in the course of making the film, you can see it.”

Life for Chen is now a little different. Since October last year, the 1.6 kilometre-long bridge has been closed while it undergoes an expansion, expected to take 27 months.

Now Chen patrols the river shore underneath the bridge, looking for the tell tale signs on stranger’s faces.

But its closure hasn’t stopped the suicides. Chen told news.com.au that despite the growing number of suicides on the bridge, he’s saving more people than ever.

“The bridge is closed since last October (2016). I saved 330 people last decade, and the number is still increasing, now I patrol the river shore every weekend,” he said.

“After the movie, nothing changed. I’m still working and I said I’ll do everything I can to help people.”

His new patrol is tougher ground than usual. He says it’s harder to save people, the long strands of grass make it “difficult to watch”.

But Chen says despite the grim nature of the job, there is hope on the horizon.

“A lot of years ago when people saw someone commit suicide, they [bystanders] just watched, but now, everyone wants to help and do something.”

- To donate to Chen Si and his mission to save lives, visit his donation page.

— Find more information and watch the Angel of Nanjing documentary here.

— Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or visit the website, lifeline.org.au.

— Do you know someone with an amazing story? Share it with us: youngma@news.com.au