By Neil Smith Entertainment reporter, BBC News

San Francisco's Golden Gate Bridge was first opened in 1937

In broad daylight, a long-haired man in black leather jacket and sunglasses mounts the four-foot guard rail that lines the pedestrian walkway of the Golden Gate Bridge.

Facing away from Alcatraz and the city of San Francisco, he takes one step backwards and plunges 225 feet into the choppy waters below.

This chilling tragedy is one of six leaps featured in The Bridge, a disturbing new documentary exploring this famous US landmark's ghoulish reputation as a suicide mecca.

For director Eric Steel, such harrowing footage was a crucial element in his analysis of what draws so many to end their lives on this most iconic of structures.

"I wanted to make a film about the human spirit in crisis," he explains.

"The point was to begin a more frank dialogue about mental illness, and it required people see these things in order to do that."

Steel and his crew spent all of 2004 filming the Golden Gate Bridge, capturing most of that year's two dozen suicides and many thwarted attempts.

Intervention

Before a single frame was shot, though, the former Disney executive ensured strict guidelines were in place to keep the authorities informed of any suspicious behaviour.

"As soon as someone put their foot on the rail, the first thing we did was call the bridge patrol," he tells the BBC News website.

Director Eric Steel and his crew spent a year filming the iconic structure

"I don't think we could have lived with ourselves if we had made any other choice."

According to Steel, six suicide attempts were averted thanks to his team's speedy intervention.

"It's not any kind of justification, but I don't know one film-maker who can say they've saved even a single life in the course of a year," he continues.

"So I think the fact that my crew and I saved six shows we went to great lengths to do what we believed in as human beings before acting as film-makers."

Much of The Bridge consists of interviews with friends and relatives of the deceased trying to make sense of their loved ones' actions.

Also included is startling testimony from Kevin Hines, one of the few jumpers to survive the four-second, 75mph descent.

Criticism

The director says that all his interviewees have given his movie their blessing and are "terribly proud" to be associated with it.

However, this has not insulated him from accusations that his film is exploitative and intrudes upon private grief.

The cost of building a suicide barrier is estimated to be $25m (£12.7m)

Steel acknowledges the criticisms but insists that his documentary "is very sensitive to the people in it and the people it's about".

"Every frame we show in the film where people die or are contemplating dying was also witnessed by other people," he adds.

"It wasn't like we were intruding. We were only recording things other people were also seeing."

The director also rejects suggestions that his film could lead others to take the same drastic steps as his late subjects.

"Of course I'm concerned about the copycat effect, but the answer isn't not showing the film.

"The answer is showing the film, having a discussion and trying to come up with local solutions to a local problem and broader solutions to a universal problem."