Five appliances were called to the museum in Downpatrick just before 0300 GMT on Thursday.

The fire is believed to have started in one of the carriages.

It was a dangerous fire from the point of view that internally there was a danger of floor collapse Gerry Toman Divisional fire officer

Years of dedicated restoration work was destroyed when the fire gutted the building and one of the train carriages on the old station platform.

The site has been sealed off for police investigation.

Damage to the station has been estimated at £250,000.

Divisional fire officer Gerry Toman said it was a ferocious blaze.

"It was a major fire and the wind and weather conditions added to the intensity of it," he said.

"We had to use a number of water jets and breathing apparatus.

"It was a dangerous fire from the point of view that internally there was a danger of floor collapse, but eventually we got things under control and thankfully nobody was hurt."