Born last July to mother Alinga and father Tanami, the animal resides at Edinburgh Zoo and weighed in at 759g.
Images of the creatures being given water by firefighters have gone viral in recent days.
Koala Hospital Port Macquarie made the decision to put Lewis to sleep as his burns took a turn for the worse and would not recover.
Rescuer Toni Doherty said it was her ‘natural instinct’ to pull the animal from the burning trees.
The footage shows the marsupial relaxing in the car's back seat, apparently taking advantage of the air conditioning.
A wildlife park in Australia has cast a glimpse into play time between one certain koala and his zoo keeper.
The Australian government has listed one of its national symbols, the koala bear, as a threatened species in some parts of the country.