When deadly wildfires swept across California in 2018, New Zealand and Australia sent more than 130 firefighters to help control the blaze.

Now, for the first time since 2010, American firefighters are providing the same lifesaving assistance to Australia.

In recent months, some of the most dangerous and widespread wildfires in Australia’s history have engulfed millions of acres and displaced entire communities. Several Australian firefighters have been killed on the job and thousands of koalas and other wild animals, some endangered, are feared to have died in the extreme conditions.

Since late last year, more than 150 American fire personnel have joined in the fight against the fast-moving blazes. Australian and U.S. firefighters have worked together and shared best practices for decades, but the current collaboration is the product of an agreement the two countries first signed in 2002 that allows them to contribute directly to each others’ firefighting efforts on the ground. Canada and New Zealand have also deployed firefighters to assist.

Elden Alexander, a fire operations specialist who works for the U.S. Bureau of Land Management, was the first American firefighter to land in Australia in November. He stayed for 35 days, representing the National Interagency Fire Center and working with Australian officials to determine what voids U.S. firefighters might be able to help fill with a high-level management team that could assist in overseeing operations and logistics.

“Their critical need at the time was fire leadership,” Alexander said.

Australia also requested assistance from U.S. aviation specialists to observe fires from helicopters and planes, and to help decide where to send firefighters on the ground and where to drop retardant or water bombs to control the fire from above, Alexander said.

Hundreds of Americans raised their hands to help, Alexander said, but not just any firefighter could sign up. They have to be federal employees with a valid passport and an Australian visa, which they could apply for online. From among those who volunteered to be considered for deployment, U.S. fire officials made selections on the basis of what skills their Australian counterparts most needed, and an initial team landed in early December.

Although there are some minor differences between Australian and U.S. firefighting techniques, the National Interagency Fire Center said in a statement that the two countries “share a common system for managing wildland fires … along with similar training regimens and physical fitness requirements.

Alexander, who started his firefighting career in Oregon in 1990 and has fought blazes across the United States, said that despite his experience, the sheer speed with which the current Australian fires were catching surprised him.

“The conditions were just so hot and dry,” he said. “Giant pastures that should be loaded with green grass and cattle were just dirt."

Even Australian firefighters who were more used to the harsh surroundings “were still kind of in shock and awe about the severity of the fires, their resistance to control and how difficult these fires were to put out,” he said.

American firefighters don’t arrive empty-handed. They bring their own protective gear, including pants, shirts and boots, and carry packs of supplies that can weigh dozens of pounds, Alexander said.

Upon arrival in Australia, U.S. firefighters were met with a warm welcome.

Videos shared on social media showed Australians clapping and cheering at the airport in Sydney when a group of American firefighters landed there earlier this month. Shane Fitzsimmons, commissioner of the New South Wales Rural Fire Service, tweeted that the crowd reflected “the gratitude & admiration we all have for their generosity.

Neil Pattinson, a volunteer firefighter from Canberra, said in a phone call that he’s thrilled that Americans have stepped up to offer assistance because so many Australian firefighters “are just exhausted.

“They’ve gone out day after day,” he said of Australian firefighters. “I think it’s fantastic that we get help.

Pattinson, who has volunteered as a firefighter since 2006, has been deployed twice in recent months and said the fires are much more intense than what he’s seen in other seasons. In some cases, he said, dry lightning will spark a fire “and the next thing, you turn around and it’s a blaze, and it’s starting to burn hectares.

“You’ve just got to be aware of your surroundings and concentrate on what you’re doing and trust your training,” he said.

According to the National Interagency Fire Center, Australia is set to reimburse the U.S. government for the costs of sending Americans to help with the fires, including their travel, meals and their salaries.

Carrie Bilbao, public affairs specialist at NIFC, said that “there’s always an interest in helping out other countries or other areas."

“Even when you’re here in your own state and you know California is burning, there is interest to go there, to help out where you’re needed,” she said.

Alexander said Australian firefighters repeatedly thanked him for taking time away from his family during the holiday season.

“My answer to them was: ‘We’re volunteering to be deployed,’ ” he said.

Many Australians from affected communities didn’t get the chance to celebrate the holidays at home either.

“It was nothing for us to come over and do that,” he said.

Read more: