Foreign Affairs Minister Charlie Flanagan has confirmed that all five victims in the Berkeley balcony tragedy in the US were young Irish citizens.
Describing their deaths as a "tragic accident," Mr Flanagan said that another nine injured, some critically, are also Irish J1students.
Speaking at a hastily arranged press conference in Government Buildings, Mr Flanagan said: "This is a terrible tragedy. It is with great sadness that I can confirm that following a tragic accident in Berkeley San Francisco, a few hours ago, five Irish Citizens have lost their lives."
He added: "This is a very challenging and difficult time for the families, for parents of those directly involved. It has been an appalling tragedy, an appalling loss of life."
"Young people with hopes and dreams for the future have suddenly been shattered," the minister said.
"There were a number of other students in the apartment, at what I understand it was a 21st birthday party, who are being treated in nearby hospitals," he added.
"A number of other students have been injured, seven, eight or nine. My understanding is that all of them are Irish," Mr Flanagan confirmed.
He said the department's consular services, headed by top official Philip Grant, is assisting those affected and is at the scene of the tragedy.
He said he had also spoken with US Ambassador to Ireland, Kevin O'Malley, who offered his condolences to the Irish people but also his assistance.
Mr Flanagan said he understood the victims were all J1 students but was not able to clarify how many of those who died were male or female.
He said he didn't have details of their identities or where they were from as the full details have yet to emerge.
5 killed in our apartment here in Berkeley. Really puts life into perspective #RIP— James Mullaney (@mullaneyjames) June 16, 2015
Government sources have insisted that some of the victims' families have not yet been notified of the tragedy.
Mr Flanagan said the process of contacting the families is being done as quickly as possible and as soon as appropriate information is available.
The minister said he did not have any details as to he cause of the deaths, but that he understood it to be a "tragic accident."