The network cites Irish Consul-General Phillip Grant, who said there were 12 to 14 people on the balcony at the time, ages 20 to 22 years old.
Irish officials said they were taking part in a student exchange summer work program.
Six people were killed, authorities said. Grant said the injured were being treated at Eden, Highland and John Muir hospitals.
The Associated Press reports that many of the wounded have critical, life-threatening injuries.
Police received a call about the incident shortly before 1 a.m. PDT Tuesday, and officers arrived to find that the balcony on the fourth floor of the building on Kittredge Street had disintegrated.
Television footage of the scene showed that the fourth-floor balcony fell onto the one on the third floor.
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The building in the heart of downtown Berkeley has apartments in the upper floors and retail shops at ground level. The walkable neighborhood just blocks from the University of California, Berkeley, is dotted with museums, restaurants, coffee shops and chain stores.
Ireland's Department of Foreign Affairs said it was trying to contact families of the victims and could not give details of their identities.
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, California today. My heart goes out to the families and loved one's of all those involved."
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 know what happened. Officers on scene are talking with people," she said.
Police were working with fire officials and building inspectors to try to determine what caused the accident, Coats said.
She said she also didn't have information on the identities of the victims.
"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 Irish consul general in San Francisco would be providing assistance to those affected, the AP reported.
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The Associated Press contributed to this report.