Flint is a horrible tragedy. But a gas leak in Los Angeles may spell an even greater environmental disaster.

LOS ANGELES — The drinking-water crisis in Flint, Mich., is both an outrage and a tragedy: a sordid tale of government cost-cutting, callousness and coverups that exposed 27,000 children to extremely high levels of lead and may have killed at least 10 people.

It has also brought attention to the wider risk of toxic lead exposure, whether from hazardous urban soil or from the estimated 3.3 million utility lines nationwide that contain the poisonous metal.

Yet at the same time Americans have been shocked and saddened by Flint — and rightfully so — another environmental calamity has been unfolding 2,300 miles away in the Porter Ranch community of Los Angeles that may be even more troublesome for more people in the long term.

SLIDESHOW – California natural gas leak >>>

“Flint is the more egregious case of neglect, and it’s far worse in terms of the human cost,” says Rob Jackson, an environmental scientist at Stanford University. “But nothing about Flint has the sort of national or global consequences that the problems at Porter Ranch have.”

That’s because, as horrific as it is, Flint is the exception that proves the rule. Lead exposure in the U.S. has declined dramatically over the past four decades thanks to government-mandated monitoring and treatment — and that isn’t going to change.

Meanwhile, Porter Ranch hasn’t received nearly as much national news coverage as Flint. But if nothing is done, what’s happening there could happen more and more throughout the U.S. in the years ahead.

The short version of the Porter Ranch story is that on Oct. 23, the Southern California Gas Co. discovered a rupture in an underground pipe linking nearby Aliso Canyon, one of the country’s largest natural-gas storage reservoirs, to the surface of the earth. Authorities soon determined that the amount of methane leaking from Aliso Canyon each day  — 2.5 million pounds, the most in U.S. history — was roughly equivalent, in terms of environmental impact, to the daily emissions from six coal-fired power plants, 2.2 million cows, or 4.5 million cars.

Local children — and pets — began to suffer from headaches, nosebleeds, and vomiting. The Federal Aviation Administration, fearing that a plane would ignite the massive methane cloud hovering over the area, instituted a no-fly zone. More than 2,500 families fled their homes. Lawsuits were filed (including new criminal charges Wednesday against SoCalGas). Businesses struggled to stay open. Property values plummeted. Even today, more than three months later, the leak still isn’t under control. All told, Porter Ranch has become one of the worst environmental disasters in recent memory, with a carbon footprint larger than the catastrophic BP oil spill of 2010.

Still, it makes sense that Flint is a bigger news story than Porter Ranch. SoCalGas waited three days before reporting the leak. In Flint, state and federal officials dragged their heels for more than a year. Residents of Porter Ranch have reported various short-term illnesses, mostly from the sulfurous odorants added to methane to aid in detection. (Experts say the gas itself isn’t harmful.) In Flint, thousands of children have been exposed to a toxin that could cause irreversible damage to their developing brains and nervous systems. Porter Ranch is an affluent, largely white community; Flint is largely poor and largely black.

But while Porter Ranch isn’t as unjust as Flint, and while the immediate human toll isn’t nearly as harrowing, the leak has exposed major problems with our growing natural-gas system that will only get worse, even after the well is capped. And this, like Flint, should be cause for nationwide concern.

SLIDESHOW — Water crisis in Flint, Mich. >>>

Aliso Canyon isn’t unique. In fact, it’s one of more than 400 such natural-gas storage sites across the country, and the vast majority of those aging facilities are likely to have the same vulnerabilities — in this case, 60-year-old pipes and a missing shut-off valve that was never replaced after breaking in 1979 — that led to the Porter Ranch rupture. Recent research estimates that natural-gas-gathering facilities alone routinely leak 100 billion cubic feet of methane each year — more gas than the entire country burns in a day.

And that’s just what seeps out on a regular basis, without any sort of catastrophic breach. According to a recent FiveThirtyEight report, the city of Boston alone had at least 1,868 documented unrepaired leaks in its gas lines as of March 2015, and the oldest has been leaking since 1985. The truth is, much of America’s natural-gas network has operated for decades with little investment in updates and inspections, and regulations — both state and federal — are outdated and underenforced. That’s left companies to decide how much they will or won’t spend to keep their gas fields modern and safe.

If the only effects of methane leakage were headaches and nausea, loose regulations and lax enforcement would be unfortunate. But what makes Aliso Ranch such a wake-up call is the staggering effect it’s having on the environment. As of Jan. 24, estimates showed that the leak had released the equivalent of 2.1 million metric tons of carbon dioxide into the atmosphere — more greenhouse gas than 440,000 cars emit in a year. Given the fact that methane’s effects on global warming are 84 times as potent as carbon dioxide’s, that’s enough gas to make Aliso Canyon the single biggest contributor to climate change in California and to set back the state’s efforts to curb emissions — some of the most aggressive in the nation — by an entire year. Similar leaks have also caused devastating explosions in the past.

At a time when new fracking technology is fueling the rapid expansion of America’s natural-gas system and generating more wear and tear on aging facilities, lawmakers should be working to prevent the next Porter Ranch. In the Golden State, Gov. Jerry Brown has issued an emergency order requiring SoCalGas and other utilities to “conduct daily inspections of wellheads using infrared leak-detection technology, verify the mechanical integrity of wells, measure gas flow and pressure and regularly test safety valves, among other steps.” Meanwhile, state legislators have proposed stringent new safety regulations for all 14 of California’s underground natural-gas storage facilities.

But Porter Ranch isn’t just a California problem; it’s a national problem. And while it may not be as tragic a tale as Flint, it has the potential to become a more familiar and environmentally devastating one if the rest of the country simply forgets and moves on.