Helicopters carry out an aerial firefighting operation as bushfires burn near Bumbalong, New South Wales, Australia, February 2, 2020. REUTERS/Loren Elliott

A helicopter carries out an aerial firefighting operation as bushfires burn near Bumbalong, New South Wales, Australia, February 2, 2020. REUTERS/Loren Elliott

A helicopter takes water from a pond while carrying out an aerial firefighting operation as bushfires burn near Bumbalong, New South Wales, Australia, February 2, 2020. REUTERS/Loren Elliott

A helicopter carries out an aerial firefighting operation as bushfires burn near Bumbalong, New South Wales, Australia, February 2, 2020. REUTERS/Loren Elliott

A helicopter carries out an aerial firefighting operation as bushfires burn near Bumbalong, New South Wales, Australia, February 2, 2020. REUTERS/Loren Elliott

A helicopter carrying out aerial firefighting operations flies through the smoke of a bushfire in Bredbo, New South Wales, Australia, February 1, 2020. REUTERS/Loren Elliott

Firefighters try to extinguish a fire at a building in downtown Sao Paulo, Brazil May 1, 2018. REUTERS/Paulo Whitaker

Firefighters try to extinguish a fire at a building in downtown Sao Paulo, Brazil May 1, 2018. REUTERS/Paulo Whitaker

Fire retardant from recent aerial firefighting seen on a leaf at the Nuns Fire just north of Kenwood, California U.S., October 17, 2017. REUTERS/Loren Elliott

A firefighting plane dumps water on a forest fire in Mendeira, Portugal June 19, 2017. REUTERS/Miguel Vidal TPX IMAGES OF THE DAY

Firemen spray the burned Beth Hamedrash synagogue in New York City, U.S., May 14, 2017. REUTERS/Joe Penney

Firemen spray the burned Beth Hamedrash synagogue in New York City, U.S., May 14, 2017. REUTERS/Joe Penney

Firemen spray the burned Beth Hamedrash synagogue in New York City, U.S., May 14, 2017. REUTERS/Joe Penney

Firemen spray the burned Beth Hamedrash synagogue in New York City, U.S., May 14, 2017. REUTERS/Joe Penney

Firemen spray water at the burned Beth Hamedrash synagogue in New York City, U.S., May 14, 2017. REUTERS/Joe Penney TPX IMAGES OF THE DAY

Fire-retardant material is seen mid-air after it was dropped by aerial firefighting squadrons during a wildfire in the northern city of Haifa, Israel November 24, 2016. REUTERS/Baz Ratner

A firefighting plane drops fire retardant during a wildfire, near the communal settlement of Nataf, close to Jerusalem November 23, 2016. REUTERS/Ronen Zvulun

A firefighting plane drops fire retardant during a wildfire, near the communal settlement of Nataf, close to Jerusalem November 23, 2016. REUTERS/Ronen Zvulun

A firefighting plane drops fire retardant during a wildfire, near the communal settlement of Nataf, close to Jerusalem November 23, 2016. REUTERS/Ronen Zvulun

A firefighter helicopter flies over a wildfire in Benitatxell near Alicante, Spain September 5, 2016. REUTERS/Heino Kalis

Firefighter helicopters fly over a wildfire engulfing a hillside in Benitatxell near Alicante, Spain September 5, 2016. REUTERS/Heino Kalis

Firefighting helicopters maneuver around power lines and smoke to make a water drop during the Blue Cut fire in San Bernardino county near the Cajon Pass in San Bernardino, California, U.S. August 17, 2016. REUTERS/Patrick T Fallon

A firefighting helicopter maneuvers around power lines and smoke to make a water drop during the Blue Cut fire at the Cajon Pass in San Bernardino County, California, U.S. August 17, 2016. REUTERS/Patrick T Fallon

Firefighting helicopters maneuver around power lines and smoke to make a water drop during the Blue Cut fire in San Bernardino county near the Cajon Pass in San Bernardino, California, U.S. August 17, 2016. REUTERS/Patrick T Fallon

A firefighting helicopter maneuvers around power lines and smoke to make a water drop during the Blue Cut fire at the Cajon Pass in San Bernardino County, California, U.S. August 17, 2016. REUTERS/Patrick T Fallon

A DC-10 fire fighting aircraft makes a fire retardant drop as firefighters continue to battle the Clayton Fire north of Lower Lake in California, U.S. August 15, 2016. REUTERS/Stephen Lam

A DC-10 fire fighting aircraft (L) makes a fire retardant drop while following its lead plane while battling the Clayton Fire north of Lower Lake in California, U.S. August 15, 2016. REUTERS/Stephen Lam

A DC-10 fire fighting aircraft makes a fire retardant drop as firefighters continue to battle the Clayton Fire north of Lower Lake in California, U.S. August 15, 2016. REUTERS/Stephen Lam

A Los Angeles County Fire Department helicopter makes a water drop at night during the so-called Sand Fire in the Angeles National Forest near Los Angeles, California, U.S. July 24, 2016. REUTERS/Gene Blevins

A firefighting helicopter passes over the so-called Sand Fire in the Angeles National Forest near Los Angeles, California, U.S. July 24, 2016. REUTERS/Jonathan Alcorn

A firefighting helicopter makes a water drop at the so-called Sand Fire in the Angeles National Forest near Los Angeles, California, U.S. July 24, 2016. REUTERS/Jonathan Alcorn

Onlookers watch and first responders salute as the hearse carrying the body of Dallas Police Department Senior Corporal Lorne B. Ahrens, who was among five police officers shot dead the previous week, drives by during a funeral procession in Dallas, Texas, U.S. July 13, 2016. REUTERS/Brandon Wade

Onlookers watch as first responders salute while the hearse carrying the body of Dallas Police Department Senior Corporal Lorne B. Ahrens, who was among five police officers shot dead the previous week, drives by during a funeral procession in Dallas, Texas, U.S. July 13, 2016. REUTERS/Brandon Wade

First responders salute the hearse carrying the body of Dallas Police Department Senior Corporal Lorne B. Ahrens, who was among five police officers shot dead the previous week, in Dallas, Texas, U.S. July 13, 2016. REUTERS/Brandon Wade

A water bomber drops down inside a canyon to lay retardant on a wildfire that continues to burn near Campo, California, U.S. June 21, 2016. REUTERS/Mike Blake

A fire fighting aircraft drops fire retardant over one of two wildfires in the Angeles National Forest above Azusa, California, U.S. June 20, 2016. REUTERS/Gene Blevins

A fire fighting aircraft drops fire retardant over one of two wildfires in the Angeles National Forest above Azusa, California, U.S. June 20, 2016. REUTERS/Gene Blevins

A C-130 air tanker makes a drop of fire retardant as a sky crane passes below over one of two wildfires in the Angeles National Forest above Azusa, California, U.S. June 20, 2016. REUTERS/Gene Blevins

A fire fighting aircraft (L) drops fire retardant as its spotting plane (R) follows above power lines over one of two wildfires in the Angeles National Forest above Azusa, California, U.S. June 20, 2016. REUTERS/Gene Blevins

A fire fighting aircraft (L) drops fire retardant as its spotting plane (R) banks over one of two wildfires in the Angeles National Forest above Azusa, California, U.S. June 20, 2016. REUTERS/Gene Blevins

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters battle a wildfire in temperatures well over 100F as it burns near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A fire fighting helicopter turns past the sun after making a drop on a wildfire near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop on a wildfire as it attacks the flames near Campo, California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters use air assets to battle a wildfire as it burns in the hills near Potrero California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters use air assets to battle a wildfire as it burns in the hills near Potrero California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters use air assets to battle a wildfire as it burns in the hills near Potrero California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters battle a wildfire in temperatures well over 100F as it burns near Potrero, California, U.S. June 20, 2016. REUTERS/Mike Blake

A San Diego Sheriff looks on as a water bomber makes a drop as firefighters battle a wildfire in temperatures well over 100F as it burns near Potrero, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop as firefighters battle a wildfire in temperatures well over 100F as it burns near Potrero, California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters work from the air to try and save a home as they battle a wildfire near Potrero, California, U.S. June 20, 2016. REUTERS/Mike Blake

Firefighters battle a wildfire as it burns near Potrero, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop as firefighters battle a wildfire in temperatures well over 100F as it burns near Potrero, California, U.S. June 20, 2016. REUTERS/Mike Blake

A water bomber makes a drop as firefighters battle a wildfire as it burns near Potrero California, U.S. June 20, 2016. REUTERS/Mike Blake

A fire fighting helicopter passes through smoke under the sun as it helps battle a wildfire near Potrero California, U.S. June 20, 2016. REUTERS/Mike Blake