Soon after I moved to my present neighborhood, I saw some policemen standing on the Calvert Street bridge. I had been walking home from work, a fine early summer dusk as I remember it, and I wondered what had drawn the police to the bridge. A crime of some sort? An accident? Then I saw them peering over the edge into Rock Creek Park, 125 feet below. A neighbor ended the mystery. Someone had jumped off the bridge, he said. It happens all the time.

Of course. The notorious Calvert Street bridge. I had paid no attention to it when I first moved into the neighborhood, although I was aware that it and the nearby Connecticut Avenue bridge are to Washington what the Golden Gate Bridge is to San Francisco -- a favorite spot for suicides. If anything, the Washington bridges are more lethal. You have to plan to jump off the Golden Gate. With the Washington bridges, you only have to be depressed and out for a walk.

Since that first time, I have seen the police come back again and again. I never look down when they do. Not everything in life has to be seen.

Recently, and seemingly without warning, an iron fence started to go up on the Calvert Street bridge. (It's official name is the Duke Ellington Bridge.) The fence, somewhat ugly but not terribly so, went up in sections -- a section here, a section there -- and then the construction stopped altogether, well short of completion. In some cities, that might seem inexplicable, but not in Washington. Here, all phenomena are explained with the phrase, "That's the District."

Anyway, I paid no attention. The neon "No Left Turn" signs on the corner of Calvert and Connecticut haven't worked in years; occasionally the traffic signals are out, too, and the street lighting is so bad drivers can't see the signs and make illegal left turns. The city allowed Sheraton to foul the neighborhood by building a hotel without sufficient parking, declared the area the world's first free-parking zone on weekends and hasn't permitted a cop into the area since 1981. After all that, it was hardly mysterious that the construction of a fence had simply stopped. Then I found out why: community pressure.

The fence was designed to stop people from jumping off the bridge into the park. Almost 40 persons have done so since 1978. One of them was the 24-year-old daughter of Anne and Benjamin Read. The Reads started the campaign to have the fences built, arguing that suicide is often the impulsive act of depressed people. If people like that are thwarted by a barrier, if their path is impeded, if they can be stopped even for a little while, they will often reconsider.

Many experts agree with them. Every once in a while, the fence can save a life.

Maybe the fences could have een made prettier. Maybe the city could have done more than it did to alert the neighborhood. Maybe there is noth fence will save lives and everything to the argument that those frustrated on Calvert Street will go elswhere to die. Maybe. But while these propositions were being argued -- while fence construction was halted by the courts -- three persons jumped from the bridge. Even for esthetics, that is too high a price.

Mayor Marion Barry says the fences will be built. Neighborhood groups vow otherwise. The Kalorama Citizens Association is opposed. So too is Ward 1 Councilman Frank Smith. He says he would prefer a net and so, I bet, would all the kids who pass over the bridge on the way to school. They'll just love to throw stuff into the net. Weren't politicians ever kids?

One neighbor asked for my help. Write something, he said. Another neighbor pronounced the fence ugly beyond words and suggested I do something. What can I do? The truth is that I would prefer no fence -- aso no need for one. To die for beauty may be noble; to have someone else do it is selfish.

The other morning I saw that work has resumed on the fences. It was cold, and four or five guys were working. I wish there were more. It's Christmas -- the holiday season. For the fence crew, it's a race against time.