After years of debate over how to save lives while still protecting the beauty of an iconic structure, San Francisco’s Golden Gate Bridge is finally getting a suicide barrier.

An estimated 1,500 people have jumped to their deaths from the span in its 80 years of existence. In 2016 alone, 39 people leaped from the bridge and died. Bridge patrol officers stopped an additional 184 people they believed were at risk of suicide. A handful of people have survived the plunge into the water.

The barrier, planned for completion in 2021 at a cost of $204 million in local and federal funds, will be a stainless-steel gray net running beneath the span for 1.7-miles on both sides, according to Golden Gate Bridge Highway And Transportation District plans. It will be suspended 20 feet below the bridge, and will extend 20 feet over the water. It won’t be visible to drivers.

The net could catch jumpers, but the hope is that it will be enough of a deterrent to keep people from even attempting suicide.

Artist conception of the barrier that will take four years to finish. #abc7now pic.twitter.com/lE9BIYYqvp — Wayne Freedman (@WayneFreedman) April 13, 2017

Politicians, city officials and several relatives and friends of people who jumped to their deaths attended a ceremony on Thursday marking the start of the project.

Kevin Hines, who survived a jump in 2000, was on hand to talk about his “instant regret” — too late, he feared at the time. “At the millisecond my hands left that rail, I had an instant reaction because the thought of suicide is different from the action,” Hines told ABC-7 TV.

Studies have shown that most people stopped from a suicide attempt on the bridge are unlikely to try again. A 1978 study of attempted suicides at the Golden Gate Bridge found that 90 percent of those prevented from jumping did not later die by suicide or other violent means.