Ulster rugby star Nevin Spence died in slurry tank trying to save father Young fans lay flowers at Ulster's Ravenhill ground in Belfast. Photograph: Paul Faith/PA A Northern Ireland family who lost a father and two sons in a weekend farming accident have confirmed that the men died trying to save each other. Ulster rugby player Nevin Spence, 22, his 30-year-old brother Graham and their father Noel, 58, died after inhaling slurry gas on the family farm near Hillsborough, County Down. Graham Spence was married with two children. A fourth member of the family who took part in the attempted rescue, Emma Spence was discharged on Sunday night from Belfast's Royal Victoria hospital. The fatal accident happened on their farm on Saturday. There were initial reports that the tragedy began when a family dog fell into the slurry pit and members of the Spence family sought to rescue it but these turned out be unfounded. Nevin Spence playing for Ulster. Photograph: David Rogers/Getty It now appears that Noel Spence slipped into the slurry tank and his two sons and then their sister attempted to rescue him but were overcome by toxic fumes from the tank. The Health and Safety Executive in Northern Ireland (HSENI) said two of its senior inspectors attended the scene on Saturday evening. "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," it said. The exact sequence of events is not yet clear but HSENI is investigating a definite line of enquiry. In a statement, grieving relatives said that the families were trying very hard to come to terms with the loss. "The three men were very close to each other in life, and that love was expressed in their final moments trying to help one another," the statement said. The family is being supported and comforted by other family members, friends and neighbours. Arrangements for a thanksgiving service for the three is currently under way and details will appear in the press in due course. Rugby fans began leaving scarves, flowers and other tributes at Ulster's east Belfast ground on Sunday. There was also a one-minute silence in honour of the Spences at the All Ireland camogie final in Dublin's Croke Park on Sunday.