A balcony collapsed Tuesday at an apartment building in Berkeley, Calif., killing five Irish students and one American student, and leaving seven others injured, authorities said.

Police received a call about the incident shortly before 1 a.m. local time Tuesday, and when officers arrived they found that the balcony on the 4th floor of the building on Kittredge Street had disintegrated.

Many of the injured have critical, life-threatening wounds, Officer Jennifer Coats, a spokeswoman with the Berkeley Police Department, said. Flanagan said four died at the scene and one at a hospital. KTVU reported late Tuesday morning about the sixth death. 

At a Tuesday afternoon news conference, Alameda County Sheriff's Sgt. J.D. Nelson identified the victims as Ashley Donahoe, 22, of Rohnert Park, Calif., Oliva Burke, Eoghen Culligan, Lorcan Miller, Niccolai Schuster, and Eimear Walsh, all 21 and from Ireland.

"We're still in emergency response mode," Philip Grant, Irish consul-general to the western United States, said at the conference, "[it's] been an extremely traumatic time for us."

"It came down really fast and chucked everybody off"

- Gerald Robinson, who drove two victims to a hospital

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"I walked out and I saw rubble on the street and a bunch of Irish students crying," said Mark Neville, who has been in the U.S. for three weeks under the J-1 visa program. Irish Foreign Minister Charlie Flanagan told reporters in Dublin that the students were in the U.S. on temporary visas.

Irish broadcaster RTE reported that there was a 21st birthday party taking place in the apartment before the balcony collapsed, according to Sky News. The building is two blocks from the University of California, Berkeley campus.

Police said they received a noise complaint about a loud party about an hour before a balcony collapsed.

Television footage of the scene showed that the 4th-floor balcony crumbled onto the balcony directly below it, on the 3rd floor.

"They were having a party-- suddenly it went down," Gerald Robinson, who was flagged down by two bloodied victims and drove them to the hospital, told The San Francisco Chronicle. "It came down really fast and chucked everybody off."

The investigation appears to be focusing on the amount of students who were out on the balcony prior to the collapse. Irish Prime Minister Enda Kenny says police told him there were 13 people on a balcony at the time.

A police spokesman told The Chronicle that people are not allowed on the balconies.

"They were having a party-- suddenly it went down," Gerald Robinson, who was flagged down by two bloodied victims and drove them to the hospital, told The San Francisco Chronicle. "It came down really fast and chucked everybody off."

Irish President Michael D. Higgins said in a statement that he had "heard with the greatest sadness of the terrible loss of life of young Irish people and the critical injury of others in Berkeley, Calif., today. My heart goes out to the families and loved ones of all those involved."

"I have been informed of the consular assistance being provided to assist all of the families involved and I have asked to be kept informed as further details emerge," he said.

Coats said officers are still investigating and she doesn't have any information on how the collapse occurred or what the people were doing on the structure at the time.

"We don't have a lot of specific detail at this point because they [investigators] are still trying to work through it all," she said in a telephone interview.

The building -- built in 2006, according to Sky News -- has apartments in the upper floors and retail shops on the ground floor.

The Associated Press contributed to this report.