The koala, nicknamed Ellenborough Lewis, was flown to Port Macquarie Koala Hospital last week after he was rescued from one of the several wildfires that have engulfed the state of New South Wales, Australia. The koala hospital said they made the very difficult decision to euthanize Lewis on Tuesday after surgeons inspected his horrific burns, which were deemed too bad to improve.

The hospital had previously warned that there was a possibility of ending Lewis' life after veterinary doctors stated that the koala's "injuries and his pain are not treatable and tolerable." Lewis and his daring rescue went viral last week after incredible footage emerged of a woman running into an intense brushfire to save him. The viral video showed the badly burned koala with large patches of fur missing, running from the fires before the woman, Toni Doherty, saved him. She poured bottles of water on him and wrapped him in a blanket. Doherty later told 9 News: "The poor koala, he was crying and screaming, because he was being burnt. He was burning underneath, on his little back legs… I've never heard a koala before. I didn't realise they could cry out. It was just so heart-rendering." Lewis' death comes as some experts warn that anywhere from several hundred to over one thousand koalas have died in the fires sweeping over New South Wales and Queensland over the last two months.

In Port Macquarie alone, it is estimated that 350 koalas have died out of a population of 600. Christine Adams-Hosking, a postdoctoral research fellow at the University of Queensland in Australia, told National Geographic: "They're such helpless little things. A bird can fly, a kangaroo can hop very fast, but koalas are so slow. They basically just get stuck where they are." Last week it was reported that the koala population is "functionally extinct" due to the difficulties of the species recovering from the fire. This was according to Deborah Tabart, the chairman of the Australian Koala Foundation.

Other koala experts, along with The Port Macquarie Koala Hospital disagreed with Tabart's assessment stating that the comments were far too alarmist. Wildlife conservationist Chris Johnson said: "We're not going to see koalas go extinct this fast. Koala populations will continue to decline because of lots of interacting reasons, but we're not at the point where one event could take them out." While the Port Macquarie Koala Hospital's assistant clinical director Scott Castle said: "Koalas are not functionally extinct across Australia. In the regions that have been fire-affected we won't know the full extent to changes in population dynamic until they are properly surveyed. It's far too broad to say they are functionally extinct."