As San Francisco hosts a citywide birthday party for the Golden Gate Bridge’s 75th anniversary, one thing that won’t be celebrated is the fact that the bridge continues to be the world’s top suicide site. Since it opened on May 27, 1937, there have been an estimated 1,600 deaths in which the body was recovered, and many more unconfirmed.

The data for 2011 underscore this reality: 37 people died jumping off the bridge last year, according to the Golden Gate Bridge, Highway and Transportation District. That’s the second-highest total in 15 years and the fourth highest in the bridge’s history. An additional 100 people were stopped from jumping. In other words, every 2 1/2 days, someone went to the bridge and either jumped or tried to jump.

The alarming number of suicides, year in and year out, tells the dark history of this iconic public structure. While we rightly admire the bridge’s beauty, grandeur, engineering and construction, how do we come to terms with its terrible allure? How do we calibrate its value as a world treasure against the real tragedies enacted on it?

The Golden Gate Bridge is a public health hazard; it doesn’t have adequate safety barriers. The Eiffel Tower, the Empire State Building, St. Peter’s Basilica, the Duomo in Florence, the Sydney Harbour Bridge and many other international landmarks have suicide barriers. But not the Golden Gate Bridge.

Ironically, the original design called for a higher railing along the walkways specifically to prevent suicides. In a last-minute decision, however, the railing was lowered to enhance the view. As a result, almost anyone can climb over it, from a 5-year-old girl (the bridge’s youngest suicide, in 1945) to the 75-year-old overweight woman who jumped in 2005. Or be thrown over it: Three children were murdered that way by their fathers, who jumped after them to their deaths (one in 1964 and two in 1993).

In 2008, bridge district officials finally voted to add a suicide deterrent to the bridge: a marine-grade stainless steel net that will stretch 20 feet below the walkways. It won’t be much different than the net that the bridge’s chief engineer, Joseph Strauss, installed to protect workers during construction — a net that saved 19 men.

No money has been allocated for the net, however, other than for the design, and even that isn’t scheduled to be completed until next year. So the deaths continue.

Some people oppose a bridge barrier because of the cost. Yet the bridge district has spent millions of dollars on other public safety improvements over the years that affect far fewer people.

Some people oppose a barrier because they think it will mar the aesthetics of the bridge. Yet other once-famous suicide sites have incorporated barriers with little or no visual impact.

Some people oppose a barrier because they think it won’t make a difference, that suicidal people will kill themselves another way. Yet numerous studies show that many suicidal people fixate on one means of death. If that means isn’t available to them, they don’t choose another means — instead, they choose to live.

In one study published in 1978, researchers at UC Berkeley led by Richard Seiden tracked what happened to 515 people who were stopped from jumping off the Golden Gate Bridge. Twenty-five years later, 94% were still alive or had died by means other than suicide. For those 485 people, it was the Golden Gate Bridge or nothing.

When bridge barriers have been installed, data show that suicides stop. In every other instance in which a barrier was installed on a landmark that was once a suicide magnet — the Colorado Boulevard Bridge in Pasadena, the Aurora Bridge in Seattle, the Bloor Street Bridge in Toronto, the Clifton Suspension Bridge in Bristol, England, the Duke Ellington Bridge inWashington, D.C., the Grafton Bridge in Auckland, New Zealand, the Memorial Bridge in Augusta, Maine, and many other sites — suicides from that landmark have ended, and there haven’t been increases in suicides from neighboring bridges or in suicides by other means. Tourism hasn’t been affected either — just lives saved.

The day the Golden Gate Bridge has a net, it will become a monument to compassion as well as beauty. That’s the day that truly will be worth celebrating.

John Bateson is the author of “The Final Leap: Suicide on the Golden Gate Bridge,” and the former executive director of a San Francisco Bay Area crisis center. In 2008, he helped draft the California Strategic Plan on Suicide Prevention.