The Berkeley apartment building balcony that collapsed, killing six and injuring seven others, may not have been built to support so many people. A former zoning board member who was part of a group that approved the balcony told the Chronicle it was just decorative, "It was definitely not large enough to be what the city would call an ‘open space balcony,’ where groups of people could stand outside. This was meant just to be a place where someone could stand out for bit, get a breath of fresh air. Not for something like 13 people."

A group of young people, mostly Irish citizens here for a summer work exchange program, were celebrating a 21st birthday at the fourth-floor apartment at 2020 Kittredge Street when the balcony started to fall sometime after midnight on Tuesday. Police were on the scene around 1 a.m., and found the chaotic scene of victims. One witness said, "I saw a bunch of bodies" that were in "piles of blood... It seemed like a movie, but it wasn’t."

The victims who died in the collapse are Irish citizens Olivia Burke, Eoghan Culligan, Niccolai Schuster, Lorcan Miller and Eimear Walsh and Ashley Donohoe, an American from Sonoma County. Seven others were taken to nearby hospitals for treatment; one male apparently has a "broken back and smashed legs."

The investigation is now focused on whether the structure was stable. The Chronicle reports, "While city officials wouldn’t comment on their initial findings, independent experts who viewed the damage in person or through photographs said it appeared rainwater had penetrated the balcony’s wood structure, causing dry rot that weakened it. Such rot, they said, can happen in just a few years if a building isn’t properly sealed from the elements."

When the building was completed, the building code required balconies to hold 60 pounds per square foot. According to NBC Bay Area, "Grace Kang, a structural engineer and spokeswoman for Pacific Earthquake Engineering Research Center at Berkeley, said the balcony's dimensions looked to her to be 4 by 6 feet, or 24 square feet. That would mean the balcony should hold at least 1,440 pounds, a total that likely would have been exceeded by 13 adults. 'They were packed like sardines, and then they were moving,' she said. When people are moving it 'may further exacerbate' the strain."

Another report says the balcony was around 30 square feet, which would mean it could hold 1800 pounds. The building code has since raised the requirement to 100 pounds per square foot.

The work-visa program for young Irish nationals to live and work in the United States brings thousands to various cities each summer. The NY Times spoke to some who participated in the past:

Fiona McGoran can still recall the sense of freedom she felt when she landed in New York in 1994. “There was six of us in a one-bedroom apartment in the West Village,” Ms. McGoran said. “It was the best summer of my life — I dreamed of it for a year afterward.”

Ciara Griffin, 24, came to Berkeley in 2011, working in San Francisco but staying here because rent was so much less. “We’re all still talking about the good times we had there,” she said.

“I am absolutely distraught for those people caught up in that tragedy over there,” she said. “This was supposed to be a trip of a lifetime, but suddenly something like this happens and it becomes an absolute nightmare.”

The program has been a source of discomfort. James Howard, 24, who went to San Diego in 2011, said it was basically “party central.”

“There were 18 of us sharing a two-bedroom apartment, and the hundreds of Irish students around us were in a similar situation,” Mr. Howard said.

“It was my first time away on my own for any length of time. I’m glad I did it, but once was enough,” he said.

Of course, there have been infamous incidents as well—such as the trashing of a Sunset apartment last year.

Flags are being flown at half-mast across Ireland to pay tribute to the students who were killed. A Dublin priest, who was holding a vigil for Olivia Burke and Eimear Walsh, who were parishioners, told the Guardian, "The tragedy is that they were heading out full of life and full of the joys of summer, they had the whole summer to look forward to and it’s the last thing anybody would be expecting that something like this would happen."