The Irish government confirmed several of the victims were Irish citizens, the Associated Press reported, while many of those hurt have life-threatening injuries.
It is not yet clear how the fourth floor balcony at the Library Gardens, which houses many University of California students, collapsed. Four people died at the scene, and one died at hospital, San Francisco TV station KRON 4 reports.
A man who drove victims of that Berkeley balcony collapse to the hospital says they are Irish and in their early 20's pic.twitter.com/v9W4TuPbBJ
— Amy Hollyfield (@amyhollyfield) June 16, 2015MORE: A "number" of young Irish citizens killed in #Berkeley balcony collapse http://t.co/V0Aez6yu38 pic.twitter.com/SXZe93dGEQ
— Cassandra Vinograd (@CassVinograd) June 16, 2015#breaking: debris from #berkeley balcony collapse. you can see clothing & drink cups. those injured look student-aged pic.twitter.com/qeQT9yMAIq
— Kristen Sze (@abc7kristensze) June 16, 2015#breaking: #berkeley balcony collapse that killed 5 is #LibraryGardens, billed as luxury apt 4 #UCBerkeley students. pic.twitter.com/IpcObMKl7p
— Kristen Sze (@abc7kristensze) June 16, 2015RTE reports there was an Irish 21st birthday taking place in the apartment when the balcony collapsed onto the one below, and then onto the path.
Some of the youths are believed to be students taking part in J-1, the US' summer exchange programme, according to reports from Irish Central.
Jennifer Coats, an officer in the Berkeley Police Department, said the force was alerted shortly after 1am to the collapse on Kittredge Street, which police believe took place at 12.41am.
"We don't have a lot of specific detail at this point because they (investigators) are still trying to work through it all," Sky reports her saying.
Charlie Flanagan, the Irish minister for foreign affairs, said it was "too early to know the full extent of this dreadful accident".
.@CharlieFlanagan expresses sympathy at Irish deaths in California. Consular Crisis Centre activated +353 1 418 0200 pic.twitter.com/YSiGMvyjXC
— IrishForeignMinistry (@dfatirl) June 16, 2015In a statement, Flanagan said: "It is with great sadness that I confirm that a number of young Irish citizens have lost their lives while a number of others have been seriously injured following the collapse of a balcony in Berkeley, California, earlier today.
"My heart goes out to the families and loved ones of the deceased and those who have been injured in this appalling accident."
#BREAKING 8 injured in balcony collapse in #berkeley. 5 people killed. Latest at 4:30am @abc7newsBayArea pic.twitter.com/EwI5DWYtPi
— ABC7 News (@abc7newsBayArea) June 16, 2015Anyone with concerns about their family can call the Ireland Emergency Consular Response Team on 00 353 1 418 0200.