California wildfires: With no water and strong winds how do you stop the blaze?
ITV News Health and Science Correspondent Martin Stew explains what caused the fires spread so quickly, leading to so much devastation
Words by James Gray, ITV News Producer
A series of deadly wildfires are continuing to ravage communities across Los Angeles, leaving fire authorities with the mammoth task of containing the blazes as soon as possible.
The fires have forced thousands from their homes, destroyed significant numbers of structures and, consequently, prompted much debate about the preparedness of emergency agencies.
Scenes on the ground have been described as akin to a "hellscape", with "total destruction" everywhere you look.
So why have the fires been so difficult to contain and how can they be stopped? ITV News explains.
What is causing the wildfires and why did they spread so quickly?
A definitive cause of the fires is still being investigated, according to the US Forest Service, but a leading theory is a type of weather phenomenon known as the Santa Ana winds.
The Santa Anas are characterised by extreme, dry winds, typically blowing from the interior of Southern California toward the coast and offshore.
In doing so they move in the opposite direction of the normal onshore flow that carries moist air from the Pacific into the region.
A lack of moisture in the air allows the winds to parch any surrounding vegetation, creating an ideal fuel source for the fires.
The dry ground and plants combined with gusty winds - which at points have reached up to 80mph - have enabled the wildfires to spread with deadly speed.
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Why are the fires so difficult to stop?
The weather conditions have also played a significant role in preventing fire authorities from containing the blazes.
Strong winds have grounded firefighting aircraft from joining response efforts by filling the skies with thick plumes of smoke.
Combined with parched vegetation, this has helped the wildfires to outstrip efforts to extinguish them.
Is Los Angeles suffering from a water shortage?
Some fire hydrants used to fight the Palisades Fire temporarily ran dry on Wednesday due to overstress caused by a lack of assistance from firefighting aircraft.
The Los Angeles Department of Water and Power was pumping from aqueducts and groundwater into the water system, but demand was so high that it was not enough to refill three one-million gallon tanks in the Pacific Palisades area, which help pressurise hydrants for the neighbourhood.
Janisse Quiñones, the department's head, said that three million gallons of water were available when the Palisades Fire started, but the demand was four times greater than "we've ever seen in the system".
US President-elect Donald Trump was among those to criticise Los Angeles Mayor Karen Bass and California Governor Gavin Newsom's water management policies.
But state and local officials and experts have forcefully hit back, saying critics were connecting unrelated issues and spreading false information during a crisis.
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How are winds hampering the aerial response?
Until Wednesday evening, strong winds had grounded helicopters and planes capable of carrying thousands of gallons of water or fire retardant.
Los Angeles City Fire Captain Jacob Raabe said aircraft resumed assisting efforts against the Palisades Fire on Wednesday evening, with similar craft expected to join the fight against the other named fires on Thursday.
In spite of the weather conditions, the Pentagon has pledged to send ten Navy helicopters to help fight the fires, according to a spokesperson for the department.
Officials expect it will be an active duty unit with Navy Sea Hawks based in Southern California that can be equipped to carry water.
The spokesperson added that the military is prepared to make four additional modular air firefighting systems available to the California National Guard - these would likely come from other National Guard units in the country.
What methods are they using instead?
Firefighters have been forced to use urban water systems in Los Angeles, which fire authorities have described as "really challenging".
Ms Quiñones explained these systems are primarily for urban use - homes and businesses - and not widespread firefighting efforts.
Videos shared online have also shown firefighters employing conventional methods to extinguish blazes, such as using a hose to propel water from a firetruck.
Dozens of teams of firefighters, meanwhile, have been recruited from outside of California to boost the size of the emergency response.
Los Angeles County Fire Chief Anthony Marrone told a media briefing on Wednesday that additional teams had been deployed from Oregon, Washington, Utah, New Mexico and Arizona.
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