6 killed in California balcony collapse during a party

A man makes the sign of the cross over his heart after laying a bouquet of flowers near the scene of a fifth-floor apartment building balcony collapse in Berkeley, California, June 16, 2015. [Photo/Agencies]

Sinead Loftus, 21, who attends Trinity College Dublin and is living this summer in a different apartment in Berkeley, said Berkeley is "the Irish hub.'' In fact, she said, "I've heard people complain there are too many people from Ireland here.''

"It's student-friendly, it's warm and it's a lot cheaper than San Francisco,'' she said.

Investigators will look at things such as whether the balcony was built to code, whether it was overloaded and whether rain or other weather weakened it, said Kevin Moore, chairman of the structural standards committee of the Structural Engineers Association of California.

Balconies are exposed to the elements, "so deterioration can play a part,'' Moore said. Weather, "overloading, inadequate design, all these things come up in the investigations.''

On Tuesday afternoon, engineering crews were inspecting jagged broken beams of wood sticking from the building, marking where the balcony had snapped off. Pieces of wood came away, falling to the ground, as the engineers touched them.

Berkeley officials said the building code at the time of construction required the balcony hold at least 60 pounds per square foot. The city's requirement for balconies has since been raised to 100 pounds.

The exact dimensions of the balcony that failed were not released. Estimates varied, with Mayor Tom Bates saying city officials thought it was about 9.5 feet-by-5 feet while Grace Kang, a structural engineer and spokeswoman for Pacific Earthquake Engineering Research Center at Berkeley, said it looked to her to be 4-by- 6 feet, or 24 square feet.

The larger estimate would mean the balcony should hold 2,850 pounds, while Kang's estimate would be half that. Kang said it appeared small for 13 people.

"They were packed like sardines, and then they were moving,'' Kang said. When people are moving it "may further exacerbate'' the strain.

The apartment building had wood-frame construction, and the balcony was cantilevered out from the building, with no additional support beneath. Both can make a balcony more vulnerable to dry rot and the effects of weather in general, Kang said.