In the early stages of a fire that swept through Pacific Palisades in Los Angeles, firefighters made an attempt to stop it in a residential area high in the rugged hills — a neighborhood that had an unusual set of fire hydrants.

Across several city blocks, on the edge of parched wild lands, water for firefighting was provided by dozens of aging hydrants, each featuring a single 2.5-inch outlet for attaching a hose. The standard for modern fire hydrants is to be equipped with a larger outlet for firefighters to draw a greater volume of water, in addition to at least one other outlet.

The older hydrants with a single 2.5-inch outlet “are not considered to be suitable for normal fire-protection service,” according to the American Water Works Association, which establishes industry standards for fire hydrants across the country. Yet a New York Times review found them present — and, in many cases, the only source of water for firefighting — in several areas of Pacific Palisades, as well as other neighborhoods of Los Angeles.

It is unclear whether the larger, more modern hydrants could have helped firefighters limit the spread of the wind-stoked fire in those early moments. But the outdated hydrants are yet another mark on a city water system that was already under scrutiny after firefighters reported running out of water many hours into their battle against the Palisades blaze.

Michael Fronimos, a fire chief in Michigan who has pressed for fire departments to conduct assessments of their hydrant systems, expressed surprise to see images of the smaller-capacity hydrants that the Times had found still operating in the Palisades. He said hydrants with larger outlets are considered preferable in part because water volume is more important than pressure when trying to put out a blaze.

“I’d rather have too much coming in than not enough,” he said.

The larger 4-inch outlets that are now more widely used have a higher flow rate, helping firefighters who want to attach a pumper truck to the hydrant in order to collect and distribute a large volume of water more quickly. Having additional outlets on the modern hydrants can provide firefighters with the ability to attach more than one hose and also with redundancy if one outlet has a problem.

The outdated hydrants were installed in Los Angeles neighborhoods decades ago. A Times analysis found that 17% of all hydrants in the city, and 24% of those within the perimeter of the Palisades Fire, had only a 2.5-inch outlet.

The city has largely embraced the national standards calling for more outlet capacity, but records show more than 10,000 of the single 2.5-inch hydrants in place — some of them allowed by city code in areas where pressure is at least 210 pounds per square inch.

Marty Adams, a former general manager and chief engineer at the Los Angeles Department of Water and Power, said he believed the single-outlet hydrants had initially been put in place in places like the upper Palisades because standard hydrants might not be able to withstand the high water pressure in those areas. But new hydrants with additional outlets can be rated to operate at 300 pounds per square inch.

Hydrants in Los Angeles are managed by two agencies, with the Department of Water and Power in control of each hydrant, while the Fire Department conducts tests and provides input on firefighting needs.

The water and power department declined to discuss the city’s hydrant system in detail but said it welcomed a review of how the water system had operated during the Palisades Fire, as well as any needed updates to city codes.

The department “is initiating our own investigation about water resiliency and how we can enhance our posture to respond to the impacts of climate change,” it said in a statement.

Fire Department officials said they could not address questions about hydrant design and placement in Pacific Palisades, referring queries to the water and power department.

Adam VanGerpen, a Los Angeles fire captain and a spokesperson for the agency, did say that the 2.5-inch hydrants had not generally presented a major problem for firefighters.

Crews can often tap more than one hydrant, he said, and a bigger concern is whether there is enough water.

In the Palisades, the Jan. 7 fire started near a bluff-top hiking trail and moved through parched brush down the hill. About 30 minutes after it began, firefighters reported to dispatchers that it was nearing homes, headed toward an area near the top of Bienveneda Avenue, about a mile north of Sunset Boulevard.

This has been considered one of the most crucial moments in the fire — a time when it was essential to try to stop it quickly before it could rage out of control, propelled by extraordinarily high winds.

That first neighborhood is equipped in some areas with the modern 4-inch hydrants, but many of those along the edge, where the fire first moved in, were the older ones with the 2.5-inch outlets, according to city data analyzed by the Times.

The fire spread swiftly through that first neighborhood and moved farther down the hill. Within three hours, it had grown to more than 700 acres, charring a wide stretch of the Palisades. In the end, it destroyed thousands of homes and killed several people.

Unrelated to any hydrant design issues, firefighters reported a catastrophic loss of water in the hydrants many hours into the blaze after the storage tanks that feed the hydrants in the upper reaches of the Palisades ran out of water. The city later acknowledged that the Santa Ynez Reservoir, which ordinarily would provide water pressure needed to resupply the storage tanks, had been emptied and shut down for maintenance before the fires began. All three tanks were eventually drained during the course of the firefight, and some of the hydrants went dry.

Municipal water systems are not designed to handle fires that are consuming numerous structures at once, and many firefighting experts have expressed doubt that anything could have been done to contain a blaze that was spreading through so many homes in such dry and windy conditions.

That is why the early moments of such a fire are so critical, said Venkatesh Kodur, director of the Center for Structural Fire Engineering and Diagnostics at Michigan State University. Fires grow exponentially, he said, so it is vital for crews to be able to combat a blaze as much as possible in the first 30 minutes.

Having 4-inch outlets, or at least the option of more than one outlet on each hydrant, might have provided firefighters in the Palisades with a better chance to alter the course of the fire, he said. He said it was likely that the hydrant issue would be explored as part of the fire investigation.