Killarney’s Chief Fire Officer estimates that up to 2,000 hectares - about one-third of the Killarney National Park - has either been destroyed or potentially destroyed.
And there are now signs that the fire will continue to blaze for a third night.
Indeed, the Air Corps has been booked for tomorrow to help douse the flames from the air, taking water from lakes in the National Park.
“The damage is horrendous,” Andrew Macilwraith, Chief Fire Officer, said.
"Not only have some of the oldest oak trees in Ireland been destroyed but also the habits of thousands of animals have also been destroyed."
Asked if the fire was started deliberately, he replied: “There was one single ignition somewhere, which has taken out one third of the landmass of the park.
“I’m no expert on regeneration, but that’s about 2,000 hectares potentially destroyed.
“We are saying the ignition site is in one area but because of the strong winds, it burned so fast.
“It’s impossible to know for sure at the moment if this was started deliberately.
“We just don’t know.
“Obviously the gardaí are aware of the fire and it’s very hard to tell at this stage tell .”
His officers were dealing with three fires this morning, and they are now dealing with two.
The lower fire in a place called Oak Wood, which is home to some of the oldest oaks in the country, is now out.
That was put out by the Air Corps dropping water from above and by using crews ferried to the fire by members of Killarney Water Rescue.
Two fires are currently burning at a high, and inaccessible level in the lark, namely around Purple Mountain.
A private helicopter, run by Executive Helicopters, was brought in by the National Parks.
It had to attend another fire elsewhere in the country and had to pull off around 4.30pm and fire crews were waiting for its return this evening.
“A lot of what’s on fire now can only really be dealt with by air support,” he said.
“The big problem has been as the day has come on, humidity levels drop, and the heat rises.
“And also the wind rises, and at the moment it is very windy and it is blowing the fire along quickly, through the gorse, and heather and undergrowth on the high levels.
“The big problem today is the wind and the fact that the ground is very strong.”
Kerry county councillor Michael Cahill said the fire is having a devastating impact on habitats and the psyche of locals.
"I have called for firebreaks to be provided around public and private forests and residential areas on a number of occasions over the years,” he said.
“Year after year, the lives of Fire Service Personnel are put at risk protecting our homes from these fires and our wildlife is being decimated. Everybody involved needs to come to the table, before lives are lost,” he said.
Earlier, a change in wind direction saw parts of the Killarney National Park blaze which were almost extinguished reignite just as the fires were being brought under control.
Up until around 2pm, the Air Corps - with the help of another privately-owned helicopter - had been ferrying 1,200-litre buckets of water taken from nearby lakes to spread over the fire that has been raging since Friday night.
The 16,800 litres they had carried until that point appeared to have put out the worst of the fire, which is mainly concentrated around Purple Mountain.
But shortly after the helicopter left the scene to get refuelled at Kerry Airport, the wind appeared to change direction and small, half-smouldering fire patches reignited, sending pillars of flames metres into the air in places along a section of a ridge line over the Gap of Dunloe, towards and area known as the Parson’s Nose.
The reignited flames sent large plumes of smoke over the gap and surrounding valleys.
Explorer Pat Falvey, who lives in the line of the fire and has been monitoring its progress throughout the day, said: “It was or appeared to be under control.
“But it has got a new lease of life, as the wind has changed from a south easterly to a wind blowing east to west.”
The Air Corp helicopter, which dropped 50,000 litres on the fire yesterday and expects to do the same today, is due to return to the scene shortly.
It comes as there were suspicions that the fires may have been started deliberately.
It is believed that a series of small fires were started in the Dinis area, off the Kenmare Road, and near an area known as the Eagle’s Nest.
The initial fires got out of control and then spread throughout the park.
The blaze is currently being tackled on top of Purple Mountain overlooking the Gap of Dunloe.
An Air Corps helicopter is repeatedly sweeping the area, back and forth overhead dropping thousands of litres of water onto the fire, which is being fanned by strong easterly gusts.
Park rangers, and staff from a variety of State agencies as well as a small army of volunteers are desperately building fire breaks by clearing vegetation in the path of the blazes, and leaving just soil.
The blaze, which started on Friday night, is one of the worst in living memory.
The last fire of this scale was in 1984, when the national park had a much larger number of staff to tackle it.
Then, it had around 50 staff but that has now dwindled to a handful.
Billy Tangney, of Killarney Jaunting Cars, said: “Nobody can say for certain what started this. But fires keep happening every year around this time and something has to be done.
“They need to bring in a rake of CCTV cameras and monitor what is going on.” Killarney Mayor Patrick Connor-Scarteen said he didn’t want to be drawn on the cause of the fire at the moment.
But he said: “Extra resources, including those from gardaí, need to be dedicated to finding the cause of the fire.” He said that long term, there also needs to be better resourcing so that the now annual spate of fires that hit the park and surrounding area can be addressed.
“Our climate is changing and we need the numbers to deal with situations like we are dealing with,” he said.