The destruction of the only intact World War Two airfield in Northern Ireland has been labelled "reprehensible" by the Department of Environment.
The control tower at St Angelo
Regular missions took off from Saint Angelo airport, near Enniskillen, during WW2 and it had been hoped that a process called scheduling would have helped to preserve the site against destruction and damage.
However, demolition work which began at the weekend and continued on Monday destroyed the remains of the wartime defences.
The chairman of the Historic Monuments Council, Richard Black, visited the site last week.
He said the defences were unique, and included intact machine gun pillboxes, trenches and a battle headquarters, much of which were underground.
Michael Coulter from the Environment Heritage Service said it was an extremely important air base as it formed part of the defences against German U-boats during the war.
"Round the airfield, the various defences were intact," he said.
"There was a control building that oversaw the whole area and would have been the command centre to control any response to an attack, plus various pillboxes and air raid shelters round about it.
The airfield was a unique historical site
"We were in the process of trying to protect all of this as an important part of our heritage, very much supported by the local people in the area."
He said it was "puzzling" that the buildings, which had existed for 60 years, were now being removed from the landscape.
World War Two enthusiast Noel Ingram, who was involved in the effort to preserve or schedule the site, said he could not believe what had happened.
"I would say there's nothing salvageable. Nothing can be put back," he said.
"And even if attempts were made to rebuild, they've lost their originality. It's a very, very sad day for the whole area, for the whole country.
"It was worth preserving for the simple reason that there isn't all that much of that sort of building left to be preserved.
"This was unique in that it was the only one where all these structures were still virtually intact and in fairly good condition."
He said local people would be absolutely devastated by what had happened.
Recent reports in the media suggested there had been an issue of concern about injury to animals in this case.
However, in a statement the DoE said fears that livestock would fall into the structures were "unfounded" as measures such as fencing could have been agreed with the land owner.
The DoE confirmed that contact had been made with the land owner with a view to preserving buildings under the Historic Monuments & Archaeological Objects Order 1995.
It added: "It is reprehensible that buildings such as these with connections to an important part of our history should be demolished or damaged."
The contribution of the Enniskillen airbase has been highlighted in a new exhibition in the Fermanagh County Museum in Enniskillen Castle.
The showcase, entitled Flight - When Dreams Became Reality, will run until 16 April.