An Ulster rugby player and two members of his family have died following an incident on a farm in Co Down.
Nevin Spence (22) died along with his father Noel and brother Graham after falling into a slurry tank on their family farm in Drumlough Road outside Hillsborough.
His sister Emma, who was rescued from the tank, is being treated for the effects of fume inhalation.
The Health and Safety Executive for Northern Ireland has begun an investigation in order to establish the circumstances surrounding the incident.
"From HSENI’s initial investigations, it understands that the three family members who entered an underground slurry tank died from the effects of exposure to slurry gases. The exact sequence of events is not yet clear but HSENI is investigating a definite line of enquiry," the executive said.
Emergency crews went to the farm shortly after 6pm yesterday following a 999 call reporting that four people had fallen into a slurry pit.
The Northern Ireland Ambulance Service (NIAS) said it sent three rapid response paramedics, four accident and emergency vehicles and an ambulance service doctor to the scene.
A spokesman for the ambulance service said: “Three were unconscious and NIAS paramedics commenced resuscitation efforts immediately assisted by other ambulance personnel.
“One of the four showed initial signs of responding to the efforts of the crews and was transported immediately to the nearby Lagan Valley Hospital, where unfortunately he died a short time later.
“Despite the best efforts of all involved the other two men died at the scene.
“A female was treated at the scene and taken to the Royal Victoria Hospital where she is recovering from the effects of fume inhalation.”
The Ulster Farmers’ Union said the incident had shocked the entire farming community. Union president Harry Sinclair extended “deepest sympathies” to the family involved.
“This news has shocked the farming community,” he said. “Our thoughts are with the family and friends of the three men who have so tragically lost their lives. We understand that a fourth member of the family has been hospitalised and we pray that they will make a full recovery.”
The Irish Rugby Football Union expressed its deepest condolences to the the Spence family.
"Nevin was an outstanding young player which was evident from his progression through the representative ranks and the game has been robbed of a very talented young man," IRFU president Billy Glynn said.
"The rugby community in Ireland is a very close knit one and there has been widespread shock and an outpouring of grief at this news."
In a statement, Ulster Rugby said it had learned of the tragic death of a "much loved and talented" member of the squad with profound sadness.
"Nevin Spence was a gifted young professional rugby player with an extremely bright future in the game," Ulster Rugby said.
"He made his debut for Ulster against the Ospreys in 2010 and represented Ulster on 42 occasions...His last game was on Friday afternoon when he played for Ulster Ravens against Munster A."
Northern Ireland First Minister Peter Robinson said on Twitter: “Deeply saddened to hear of the tragedy in Hillsborough this evening. My thoughts and prayers are with family at this time of devastation.”
Tributes have poured in from across the sporting world for Spence and his family.
His former Ulster team-mate Ian Humphreys said on Twitter: “Devastated to hear the news about Nevin Spence and his brother and dad. Prayers with all his family... RIP Nev, you’ll never be forgotten...”
Northern Ireland golfer Rory McIlroy also tweeted his condolences, saying: “Just heard the tragic news of Nevin Spence and his family. Makes you cherish every day you have on this Earth”.
PA