LOS ANGELES — Not since the Beach Boys were in peach fuzz and crew cuts has it been so safe to live and play in the City of Angels. Believe it: you are more likely to be murdered in Columbus, Ohio, or Tulsa, Okla., than in the nation’s second most populous city.

“You have to go back to 1957 — when I was four years old! — to find a similar period,” Charlie Beck, the Los Angeles police chief, was telling me. “How crazy is that?”

It’s “Dragnet”-level crazy, yes. But more than that: it’s one of the great urban surprises in a place that continues to defy its dystopian destiny.

By now, in the midst of a ragged recession, with another half-million people added to its burdened turf over the last 15 years, Los Angeles was supposed to be “Blade Runner” in 3-D.

“The Book of the Apocalypse Theme Park” was how the writer Mike Davis described it in his classic 1999 book, the nonfiction horror story “Ecology of Fear.”

I count myself among the visitors here who felt a palpable sense of relief flying out of L.A. in 1992, when riots over a racially charged police brutality verdict left 53 people dead and National Guard troops in the streets. The sense of menace, of collapse, of utter unsustainability was strong. What a pit, I thought, and a pity.

The image stuck in my mind was that brutal scene at the intersection of Florence and Normandie, where truck driver Reginald Denny was randomly pulled from his rig and beaten to a pulp by thugs. All captured live on television.

Since then, homicide is down nearly 80 percent through this year, and overall violent crime has taken a similar plunge. In 2008, the last year for full F.B.I. statistics, even Omaha, Neb., had a slightly higher murder rate than L.A.

And the trend continues: murder in L.A. is now down 50 percent from the relatively placid levels of two years ago. At this rate, blood-chasing local television news stations will have to import footage from other cities to uphold their reputation for practicing the nation’s worst and silliest local reporting.

I returned to that morbidly iconic intersection this week and it felt like, well, Omaha on a good day. Businesses, both chains and family-run storefronts, perked along. The nearby neighborhoods were mostly graffiti-free, with well-kept yards, churches and schools, and the rarest of real estate tags this year: a “sold” sign.

Of course, some dangerous ambient conditions remain. Chief Beck says there are still 40,000 gang members here — enough to fill a stadium— but that number is down by half from its peak. And, on the public relations front, the L.A.P.D. itself stumbled this week when it had to apologize for an insensitive display of evidence at a Las Vegas homicide exhibit, a show that included bloody clothing — since removed — worn by Sen. Robert F. Kennedy on the night he was assassinated.

Nationwide, the story of crime falling to half-century lows is an ongoing miracle. How New York went from the crack-addled days to tourist theme park is well known. But it’s a pattern that’s been repeated all over the United States, with the exception of a few hard patches — cities like New Orleans, Detroit and Baltimore.

The causes are many, and mostly speculative:

A high-tech mapping strategy, where police move on crime hot spots in something close to real time, was pioneered in New York and mastered here (give praise to William Bratton, who oversaw the departments in both cities, for that effort); the stuffing of prisons with career criminals also gets much of the credit; the role played by legalized abortion, according to the authors Steven Levitt and Stephen Dubner in their book “Freakonomics,” in preventing a generation of unwanted children from being born; and the settling down of the drug trade, the source of so much violence during the formative years of narcotic fiefdoms, to such a degree that in many parts of the city there are now more medical marijuana dispensers in Los Angeles than Starbucks outlets (regulated retailers creating an ecosystem of nonviolence).

The experts foresaw a generation of “superpredators” prowling the streets. Moralizers with microphones predicted imminent social collapse. And with the Great Recession of 2009, and particularly 2010, the positive news would surely end, in the view of James Alan Fox, the oft-cited criminologist.

Didn’t happen. Hasn’t happened. Probably won’t happen. Everything they knew — all the scary talk, with L.A. as the centerpiece — was wrong.

You saw a glimmer of hope on the day Denny was dragged from his truck. A resident of that tough neighborhood who had watched the beating live on television risked his own life to get the trucker to the hospital.

The most crime-ridden communities were never as nihilistic as portrayed in 1992. But the bad guys did have the upper hand, in part because of the police. The L.A.P.D. had a notorious reputation — corrupt, racist, incompetent — that made a mockery of its motto to “protect and serve.”

Places like South Central Los Angeles were “a hated landscape,” says Chief Beck, a 32-year veteran of the force. Helicopters constantly buzzed overhead in the harsh sunlight, a soundtrack of dread. “It was just pure hatred, on both sides.”

Chief Beck has seen crime-fighting in Los Angeles — often, an oxymoron at that — through the eyes of three generations: his dad was a cop, and his children are cops as well.

He says these are among the best years ever. Los Angeles is on a pace for about 230 murders this year, in a city of nearly 4 million people. And the department clears — solves and prosecutes — more than 80 percent of the homicides, well above the national average for big cities.

Using civil injunctions to cripple many gang activities, and former gang members to bring peace through community outreach, the city has been able to shrink the geography of hatred.

At times, Los Angeles still feels fragile, a sprawl of hubristic nature-defiance, unable to shake its noir sketchiness. If a half-inch of rain calls for breathless TV updates and canceled social events, what would a serious earthquake do to the hard-won stability of the new civic order?

Chief Beck has his fingers crossed. “Absent some huge social disorder, this will be a golden age of policing,” he predicted. “I have been to every neighborhood of this city and the most popular piece of government now, by far, is the police officer.”