Los Angeles fires: 3 reasons why they are ‘the most destructive’ in the city’s history

At least five wildfires are ravaging the city of Los Angeles, on the west coast of the United States, three of which have been described as “out of control” by humanitarian authorities.

According to several local agencies, the fires caused the deaths of six people and dozens of injuries, as well as the destruction of more than 2,000 homes and buildings.

Nearly 130,000 people have had to evacuate their homes and it is estimated that economic losses could reach $10 billion.

Those affected by the fierce fires range from famous Hollywood actors such as Billy Cristal and James Wood and personalities such as Paris Hilton to residents of the coastal area and the city’s westernmost neighborhoods.

Fire chiefs leading the firefighting efforts said that given the magnitude of the flames in some areas – such as the Hollywood Hills, home of the famous Hollywood sign – there is “no possibility” of containing them.

According to Anthony Marrone, one of the main fire coordinators, the low humidity in the area, the so-called Santa Ana winds – with speeds close to those of a hurricane – and the lack of infrastructure were the main causes of the enormous devastation. .

“We don’t have enough firefighters to deal with four fires of this size at the same time. Maybe one or two medium-sized wildfires, but not this one,” he said.

On BBC Mundo we explain three main reasons why the Los Angeles fires are considered the most destructive in the city’s history.

The biggest reason firefighters failed to contain the Los Angeles blaze may have a Santa Claus name: the Santa Ana winds, which officials say reached up to 100 miles (161 kilometers) per day. hour in fire zones.

And this has two effects that multiply the strength of the flames.

On the one hand, according to meteorologist Simon King, BBC weather presenter, these are dry winds that wick moisture away from vegetation and make it easier for fires to start and spread more quickly.

And once they start, the same winds help them spread easily.

Additionally, according to Marrone, this means that the strategy for putting out a fire of this magnitude can only be based on the hydrants the city has, since planes and helicopters cannot be used due to the force winds.

Santa Ana winds occur when a large area of ​​high pressure settles over the western United States around the Great Basin, an area that includes much of Nevada and Utah, Idaho and southeastern Oregon, says BBC meteorologist Matt Taylor.

For its part, a publication from the American National Weather Service (SNM) notes that these regions are generally dry and desert, which means that dry winds are generated there which flow from east to west and reach California without humidity.

This phenomenon occurs many times throughout the year.

“A Santa Ana episode typically occurs during the colder months, from late September to May, and lasts only a few days. But on rare occasions it can last up to a week,” adds Mr Taylor.

One of the problems reported by firefighters battling the flames is the water supply system.

Due to the lack of air support due to winds and smoke, firefighters were forced to use only the hydrant system or urban fire hydrants to control the progression of the flames.

And although municipal authorities have acknowledged that the water system of which the hydrants are a part functions adequately for the urban environment, it is not best suited to fighting fires of this magnitude.

“Fighting fires with multiple hydrants extracting water from the aqueduct for several hours is not sustainable,” said Mark Pestrella, Los Angeles County public works director, at a press conference. .

And he gave the example of fighting fires in the Palisades area.

This part of the city has three reservoirs to supply fire hydrants. On Tuesday, when the fires broke out, the first tank was emptied at 4 p.m. local time. The second four hours later and the third, at three in the morning on Wednesday.

At that point, firefighters ran out of water because the demand was far greater than how quickly the tank could be replenished. And the fire remained unstoppable.

The dry hydrants have sparked a wave of criticism on social media, including from President-elect Donald Trump, against the water management policies of Los Angeles Mayor Karen Bass and Governor of California, Gavin Newsom, a Democrat.

But state and local officials, as well as experts, responded forcefully, saying critics were conflating unrelated issues and spreading false information during a crisis.

State decisions about water distribution are not the cause of hydrant failures, they said, nor is the general lack of supply in the area.

Jay Lund, a professor of environmental engineering at the University of California, adds that Los Angeles’ water reservoirs are designed to fight fires located in homes, not in open spaces.

“The problem is not that there is not enough water in Southern California, the problem is that there is not enough water in this particular region of Southern California during the few hours it takes to fight the fires,” Lund told the Reuters news agency.

Pestrella recalls that forest fires are controlled with aerial releases, which in this case cannot be used.

“Air support is essential to fighting the fire and unfortunately the wind and air visibility prevent this,” he says.

According to BBC environmental correspondent Matt McGrath, one of the reasons for the ferocity of the fires in Los Angeles has to do with what scientists call “weather whiplash.”

“While the powerful Santa Ana winds are the key element in fueling the fires, the extremely dry conditions have made local vegetation very vulnerable to ignition,” notes McGrath.

And he cites a study from the University of California, which says that global warming has caused the oscillation of climatic conditions in this region to increase the intensity of wildfires.

The study notes that this is linked to increasingly frequent episodes of “weather whiplash”, during which there is a sudden change between extremely wet and extremely dry conditions.

So after decades of drought in California, there were a few years of extremely heavy rain, and then very dry conditions returned in recent months.

This led to rapid vegetation growth during wet years, but this abundant vegetation is now dry and more prone to fire.

The authors say climate change has increased these types of “bullwhip” phenomena globally by between 31% and 66% since the mid-20th century.

“As the planet warms, this means that the rate of increase in whiplash is accelerating in many parts of the world, not just California,” they add.