SAN FRANCISCO  After decades of debate, and unknown numbers of lost lives, the board that controls the Golden Gate Bridge took a major step toward building a suicide barrier on Friday, voting to erect a net under the span.

The 14-to-1 vote came after several failed efforts over the years to support a physical barrier on the Golden Gate, where troubled souls have long leapt to their deaths.

The current plan still must pass a final environmental review, including a look at how a net might affect pelicans and cormorants, which frequent the bridge. It also needs financing: the estimated cost of the metal net is $40 million to $50 million.

Despite the uncertainty, supporters of the plan hailed the decision. “This is a red-letter day in the history of San Francisco,” said Dr. Mel Blaustein, the president of the Psychiatric Foundation of Northern California, which has lobbied for a barrier. “It’s a suicide magnet. And sometimes all they need is a certain amount of time to stop and reflect and change their mind.”