Police in the Irish capital believe all those involved knew one another; a 14-year-old boy remains in hospital with serious injuries and an arrested man – in his 20s – is still in custody.
Irish police have named the three siblings who died in a “violent incident” at a house in Dublin.
Lisa Cash, 18, and her twin siblings Christy and Chelsea Cawley, 8, were found at a property in Rossfield Estate, Tallaght, at about 12.30am on Sunday.
They were taken to hospital in Crumlin, but were later pronounced dead.
Police said their mother, in her 40s, has been discharged from hospital, while the victims’ fourteen-year-old brother is still being treated for serious but non-life threatening injuries.
A man in his early 20s arrested at the scene continues to be detained.
Police believe everyone involved knew each other and described the scene as violent, challenging and traumatic.
Post mortems were scheduled for Sunday afternoon and Monday.
The scene – in the west of the Irish capital – remains sealed off while forensic examinations take place.
Upstairs windows of the house were open and smashed, and there were bloodstains on the window frames. A smashed downstairs window was also open.
Items including a shoe, black coat and small bag were removed from the scene in forensic bags.
Fianna Fail councillor Charlie O’Connor said the incident had caused “deep shock” in the community.
“People are really, really upset,” he said.