Up to 55 firefighters were called in yesterday to tackle a blaze that caused extensive damage to one of Roscommon town's oldest family businesses, O'Gara's Royal Hotel on Castle Street.
Seven guests and one staff member were immediately evacuated from the hotel after the fire broke out shortly before 9am.
Nobody was injured.
The cause of the fire is unknown, but it is understood that it may have originated in the first floor area.
It quickly spread to the Castle Suite ballroom on the second level of the two-storey hotel, which was completely destroyed by flames.
Firefighters from Roscommon town, Strokestown, Elphin, Lanesboro and Longford town were called to assist in bringing the fire under control.
A large hydraulic platform was also used to tackle the flames as gardaí assisted in the operation by blocking off the streets and diverting traffic.
Roscommon fire service was alerted to the fire by a female staff member from the hotel just before 9am.
The bar area of the hotel was destroyed, while part of the accommodation, comprising 22 bedrooms, was also affected.
An adjacent live venue, known as "Jack's" and which is owned by the hotel's owners, the O'Gara family, also went up in flames.
There were fears that the adjoining Mac's Bar and Rockford's Nightclub, also owned by the O'Gara family, would be badly damaged by the spreading flames, but firefighters managed to bring the blaze under control in time.
From 9am onwards a large crowd of onlookers gathered in the Castle Street area as one of the town's oldest family businesses went up in flames.
Firefighting crews remained at the scene throughout yesterday afternoon and evening, dampening the still-smouldering building.
Chief fire officer with Roscommon fire service Cathal McConn said: "This is definitely the worst fire in Roscommon town in recent times.
"We don't know the cause yet, but that is something that the forensic fire section of the Garda will be investigating and we will be doing everything we can to assist them."
Mr McConn said the main concern was to make sure the building was safe and to prevent the flames from spreading into adjoining buildings on Castle Street.
There was major traffic disruption in Roscommon throughout yesterday with the centre of the town sealed off.
The hotel has 25 full-time employees along with about 50 part-time workers.
John O'Gara, whose family has owned the hotel since 1962, was a star footballer for Roscommon throughout the 1970s and 1980s. He was centre-forward on the Roscommon team which was defeated by Kerry in the 1980 All-Ireland final.
The hotel is owned by his son Larry and his wife Aileen.