A father of three died and his wife was lucky to escape after their car plunged into a lake.
Shane Donnelly (38), from Ballyjamesduff, Co Cavan, died when the car in which he was a passenger drove off an open slipway in a tragic error during heavy rain.
His wife Aisling (34) was driving the car at the time but it is understood that she was unaware that they were parked so close to the water.
It was dark at the time of the tragedy and a heavy downpour further hampered visibility.
Mr Donnelly was a highly respected local government official and former town clerk at Navan Town Council in Co Meath.
The accident happened at around midnight on Saturday at Grange Lake on the River Shannon near Strokestown, Co Roscommon.
The couple had been attending a family dinner at the lakeside Silver Eel restaurant to celebrate the 40th birthday of Mr Donnelly's brother, along with his parents, two other brothers and their wives.
Shane and Aisling had left their three children, aged six, four and two, in the care of Aisling's parents in Roscommon. Their youngest daughter, Sarah, turns three in February.
It is understood that Shane had driven to the event and that afterwards Aisling was about to drive off to collect the children when the accident occurred.
Unaware that they were parked at the top of a slipway and in the pitch dark, Shane instructed his wife to "drive straight on".
When the car entered the lake, Aisling was able to free herself but was unable to assist her husband, who struggled because of difficulties with his seatbelt.
Swimming to shore, she quickly raised the alarm since another car was exiting the carpark at the time.
They managed to get Mr Donnelly from the car but were unable to revive him and he was subsequently pronounced dead.
Strokestown parish priest, Fr Ciaran Whitney, who attended the scene and administered the last rites, said it was a very tragic situation.
A post-mortem examination will be carried out today at Roscommon General Hospital.
Mr Donnelly worked with Meath County Council as a meetings administrator and was formerly town clerk in Navan.
He is widely credited for many improvements and initiatives in the area, such as the Navan Arts Trail.
Colleagues and friends at the council were in deep grief yesterday as news of his death broke.
Councillor Shane Cassells said he was "absolutely gutted" at the news.
He had been celebrating his son's christening yesterday when he received the news.
"My heart is broken for him, for Aisling and for their young children," he said.
"We attended each other's weddings. He was a great personal friend as well as a colleague.
"He was an amazing man and a visionary -- an exceptional public servant. The advancements in Navan are in great part due to him. He was a young man with great vision," Mr Cassells said.
He revealed how the family had been living in Navan but in recent years had moved to Ballyjamesduff in Mr Donnelly's home county of Cavan.
Councillor Niamh McGowan worked closely with Mr Donnelly during her time as cathaoirleach with Meath County Council last year.
She recalled emotionally how, having badly injured her back, Mr Donnelly "insisted" on collecting her from her home and driving her to and from the ceremony to name the Boyne bridge for Mary McAleese.
Meanwhile, a young man has died following a single vehicle accident on the Cork-Waterford road in which the weather may have been a factor.
The accident at Muckridge outside Youghal, east Cork, happened at 7.15am on Saturday.
He was named locally as Anthony 'Tony' Dineen (28) who was from east Cork and a keen GAA player.
Mr Dineen played with Eire Og and the club paid tribute to him as "a stalwart club servant and quiet, hard-working man".
The accident occurred on a stretch of the Youghal bypass a short distance from Youghal Bridge over the River Blackwater estuary.
The 28-year-old driver was critically injured when his vehicle went out of control and crashed into a concrete bridge support.
He was treated at the scene by paramedics and airlifted to Cork University Hospital by an Irish Coast Guard helicopter.
However, he was pronounced dead on arrival.
A full post-mortem examination was carried out at CUH.
Anyone who may have witnessed the crash has been urged to contact the gardai at Midleton on 021 4621550 or the Garda Confidential Line on 1800 666111.