That is why the early moments of such a fire are so critical, said Venkatesh Kodur, the 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 four-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.

“There are a lot of lessons to be learned,” he said.

Other places in California have moved to eliminate the old-style hydrants, among them the city of Santa Maria, which is replacing about 20 remaining wharf-style hydrants, each equipped with a single 2.5-inch outlet, at a total cost of about $200,000. Shad Springer, the city’s director of utilities, said the transition to more modern hydrants had made it easier to maintain them.

“It would also improve the fire flow for the firefighting — there is no doubt that would be part of it as well,” Mr. Springer said.

Fire experts said the review of water supply issues in the Los Angeles-area fires would most likely look much further than storage tanks and hydrant capacity, to include an even broader re-evaluation of whether drought-prone Southern California has access to enough water to fight blazes that can consume an entire neighborhood at once.

Rick Swan, a former deputy chief at Cal Fire, the state fire agency, said it would be ideal for all cities to install large-valve hydrants. But he acknowledged that changing out decades-old hydrants, installed when guidelines were different, could be a large task. “It’s an expensive undertaking to do any of these things,” he said.