The victims have been identified as Ashley Donohoe, 22, from Rohnert Park; Olivia Burke, 21, from Ireland; Eoghan Culligan, 21, from Ireland; Niccolai Schuster, 21, from Ireland; Lorcan Miller, 21, from Ireland; Eimear Walsh, 21, from Ireland.
Donohoe's cousin was one of the five victims who were from Ireland.
PHOTOS: Several killed in balcony collapse in Berkeley
"It looks like it may have collapsed from the fourth floor and then struck the third floor balcony, which is below it, but we don't know specifically how it happened at this point. That will all be part of the investigation," Berkeley Police Department spokesperson Jennifer Coats said.
READ MORE: A look at past US accidents involving balcony collapses
The Board of the United Irish Cultural Center released a statement saying: "Heartfelt condolences, prayers and support are coming to all for the terrible tragedy in Berkeley. The United Irish Cultural Center, its staff, all of its members and Board stand ready to help and support in any way that we can as this incredible tragedy unfolds. The Consul General Philip Grant will let us know if there is any way that we can be of immediate support/help at this point in time. We stand ready for a long term commitment to help as well."
RAW VIDEO: Berkeley officials held press conference about balcony collapse
Irish Consul General Philip Grant is in the Bay Area and said his heart was broken. "It's something that has left us all frozen in shock and disbelief."
"It is too early to know the full extent of this dreadful accident, but I have opened my department's Consular Crisis Center and activated our emergency response line so we can provide assistance and guidance to the families of those affected and to others who have concerns," Irish Foreign Affairs Minister Charlie Flanagan said in a statement.
Witnesses say the group was celebrating a 21st birthday when the fourth floor balcony they were standing on collapsed, dumping them 40 feet onto the sidewalk. "I was woken up by my parents who thought it was an earthquake," Jason Biswas said.
Biswas lives nearby and said the whole building shook. Then, he heard screaming and ran downstairs to find people lying bloody in the street. "It was very sad. I couldn't stay there for too long. It was a lot to look at," he said.
The balcony seems as though it folded over, breaking apart from the stucco wall. Police say they are doing all they can to figure out why this happened and keep people back from this potentially dangerous scene. "Right now street is closed for safety reasons because we don't know what caused this collapse and we are also concerned the balcony might fall to the street," Berkeley Police Department Ofc. Byron White said.
The victims are being treated at three different hospitals, including Eden Medical Center, John Muir and Highland Hospital.
Police did receive a noise complaint around midnight but did not respond. "We did not respond to that call because four minutes after that call came in we received multiple complains of shots being fired in South Berkeley, so of course that's a higher priority call so that's where our officers were dispatched to," Berkeley Department Police Chief Michael Meehan said.
Five of the victims were from Ireland, working for three months on a J-1 visa and excited about spending the summer in the Bay Area.
"I think we're all just really shocked and overwhelmed," Irish student Gemma Parsons said.
Parsons is from Ireland on the same program and is among the many who have left flowers outside the police tape.
Shocked & heartbroken by tragic balcony collapse. My heart goes out to the victims, their families & the Berkeley community.— Rep. Barbara Lee (@RepBarbaraLee) June 16, 2015
ABC7 News is getting new insight into the tragedy from emergency responders as radio conversations from 911 calls started pouring in to Berkley fire and police dispatch starting at 12:41 a.m. "RP (reporting pary) advising that one of the balconies broke and at least 10 people fell," a dispatch operator said.
"Not sure if this going to be a structural issue or if they were just playing around on the balcony and fell off," another operator dispatcher said.
Investigators are talking with building inspectors to get a better idea of what may have caused the balcony to collapse.
Father Mcbride from the Irish Immigration Pastoral Center arrived at Highland Hospital to counsel grieving students who have been there all morning to check on the status of their friends.
ABC7 News talked with Highland Hospital's spokeswoman a short while ago, who had this to say about their patients and the doctors treating them. "Our healthcare professionals are focusing on the patient's. That's their first priority," Jerri Randrup said. We've had these situations before, we're a trauma center we are well prepared to deal with these kind of situations."
The tragic news was generating panic among their families overseas. "All our phones were going off from our parents calling us. I woke up this morning with 27 missed calls from my mom," Parson's said.
Investigators in cranes have been taking pictures and assessing the damage, trying to figure out what went wrong. It's unclear how much weight the balcony was designed to hold.
The balcony collapse has been traumatic for families on both sides of the Atlantic. The consul general of Ireland says the first families of the dead and injured will be arriving Monday evening and have asked for privacy.
The consul general of Ireland for the Western U.S. said this was supposed to be the start of a memorable summer when 8,000 Irish college students go to the U.S. to work and learn. "This is normally the high point. This is normally a life-forming experience. It's deeply, deeply tragic and it touches every single family in Ireland," Grant said. The grief caused by the balcony collapse will be felt across Ireland and certainly among the group of students. "We got around 700 Irish students in the Bay Area at the moment and there's very few of them who wouldn't know someone who was at that party or someone who was unfortunately was injured or unbelievably lost their lives."
Berkeley Mayor Tom Bates assured reporters a thorough investigation will be conducted to learn why the balcony gave way. Extra scrutiny will be given to 13 projects currently under construction. "It's a wake-up call. We have all these buildings that are under construction and we want them to be built perfectly and we want them to be solid. We want them to hold up and we certainly don't want this kind of thing to happen," Bates said.
The building owner from investment firm Blackrock issued a statement saying: "We are terribly saddened by the tragic accident and our hearts go out to the victims and their families. An independent structural engineer is being dispatched to conduct a thorough review of the situation."
The Library Gardens building is newly renovated and marketed to students. According to the Berkeley Daily Planet, the building was supposed to open in 2002, but it stayed empty for a long time because the developer backed out.
The first building was finally completed in 2006 and the second building in 2007. Then, the complex was sold and is now managed by a Houston-based developer called Greystar, which manages five other buildings in Berkeley.
Anyone with concerns about friends or family should call the Emergency Consular Response Team at +353 1 418 0200.
Several of the students worked at Fisherman's Wharf. ABC7 News spoke with a woman from Ireland who lived close to the accident.
"I was asleep when I heard fire brigades going by 2 a.m. maybe. I really don't know because I was asleep. We were awoken around 4:30 a.m. by our parents' texting to see if we were okay," said Andrea Gainford, Wexford, Ireland.
The Irish Immigration Pastoral Center in San Francisco helps coordinate the J-1 visa program that many of the young Irish students used. Several members of the staff are at the hospital helping grief stricken students.
Father McBride from Irish Pastoral Immigration Ctr. Here counseling Irish students affected by tragedy pic.twitter.com/skVZHHBhyQ— Janet O (@JanetONews) June 16, 2015
Heartfelt sympathy & condolences to the families, friends & loved ones of the Irish students who lost their lives in Berkley this morning.— Kevin O'Malley (@USAmbIreland) June 16, 2015
The complex is a block from the UC Berkeley campus. It has apartments in the upper floors and retails shops at ground level.
Click here to find out how you can support the Irish students currently in Berkeley during this difficult time.
A crane is now in place- looks like they will soon make first attempts to get near the Berkeley Balcony that fell. pic.twitter.com/rpCaO1BuHE— Amy Hollyfield (@amyhollyfield) June 16, 2015
Andrea Gainford of Wexford heard the sirens following balcony collapse. Then texts came in from family in Ireland. pic.twitter.com/HSg2W5SLHG— Lyanne Melendez (@LyanneMelendez) June 16, 2015