Alameda County District Attorney Nancy O'Malley announced Thursday that her office will conduct a criminal investigation into the balcony collapse that killed six in downtown Berkeley on June 16.
O'Malley said it will include forensic and laboratory analysis, making it broader in scope than an investigation completed by the city of Berkeley Tuesday. The probe will determine whether there was criminal negligence that led to the deaths. If negligence is found, a possible charge would be involuntary manslaughter.
"The negligence that we'll be evaluating must be aggravated, culpable, gross or reckless," she explained, "and it must be conduct that is such a departure from what could be the conduct of an ordinarily prudent person, or careful person, as to be incompatible with protecting life."
Five of the six people killed were Irish nationals. Speaking to the families of the young people who were killed, O'Malley said, "Each of you deserves to have this case thoroughly and exhaustively investigated. We will do so, and that is the pledge I make from my office."
Update, 10:10 a.m. Wednesday:
City of Berkeley building inspectors are confirming what several independent experts said in the wake of last week's fatal balcony collapse: The lumber that was supposed to support the structure showed signs of extensive dry rot.
But in a press conference Tuesday, the city also said that even though it's not known how water got into the balcony structure and caused it to deteriorate, its investigation into the collapse is over.
"Our analysis is complete and we the city are not going to be conducting any further investigations," said Eric Angstadt, Berkeley's director of planning and development. City spokesman Matthai Chakko added that the city is not conducting a criminal investigation into the collapse, which killed six people -- apparently the deadliest single incident in Berkeley's nearly 150-year-history.
The Alameda County District Attorney's Office is "reaching out to the city of Berkeley" and "will begin looking at this matter," Assistant District Attorney Teresa Drenick wrote in an email response. The office is not providing any further details.
San Francisco-based Attorney David Anderson represents plaintiffs pressing personal injury claims against property managers. He said criminal charges are unlikely.
"It's highly unlikely that there was anything deliberate, purposeful or even a conscious disregard of safety," he said, adding the building's owner and property management company would likely face civil litigation, though. "If you're going to accept rent, you've got to use some of that to pay to keep the place safe for people that are using it."
The disaster occurred last week at the Library Gardens apartment complex, a development on downtown Berkeley's Kittredge Street completed in 2007. The six people who died -- five of them students from Ireland working in the Bay Area for the summer -- plunged to the street when the fifth-floor balcony failed during a party. Seven other students were severely injured.
The balcony, which was roughly 4½ by 8½ feet, was supported by laminated wood joists that projected out from the building's exterior wall in a cantilever -- meaning its support ultimately depended on the joists being securely tied into the structure's framing.
Those joists immediately became the focus of the investigation into the collapse.
A report released by Berkeley officials on Tuesday (and embedded below) details a series of inspections beginning less than two hours after the 12:41 a.m. collapse. Initially, the report says:
The inspectors observed from the exterior French doors of Unit 405 that the cantilevered balcony joists had completely sheared off approximately 16-20 inches from the exterior building face. ... The inspectors observed that the deck joist ends protruding from the exterior wall appeared to be severely dry rotted.
And subsequent inspections by daylight confirmed that impression. The city's supervising building inspector, Patrick Emmons, was hoisted on a platform to get a close-up look at the collapsed balcony, and observed "that the joist ends protruding from the exterior wall appeared to be extensively rotted at the failure points."
Inspectors also found dry rot in the balcony immediately below the one that collapsed. They ordered that balcony removed.
Angstadt, the city planning director, cautioned that the inspectors' findings are not a formal determination of the cause of the balcony collapse.
"What our observations were is there was severe deterioriation of the wooden structural members," Angstadt said. "The most likely cause of that deterioration was dry rot, and the most likely contributor to dry rot is moisture infiltration."
Angstadt also said the city is not investigating how the moisture got into the interior of the balcony.
"We don't know and we're not going to know or determine how the moisture got into the assembly," he said. "What we're going to do is make a set of recommendations that will hopefully deal with any form of moisture infiltration to closed assemblies in the future."
Those recommendations for emergency changes to the city's building code include improved ventilation for the enclosed portions of balcony support structures, requiring the use of resistant or specially treated wood and mandatory inspections every five years.
Several media outlets have reported that the general contractor on Library Gardens, Segue Construction, has faced a series of legal actions connected to water damage and dry rot in several Bay Area apartment projects.
The San Francisco Chronicle reported Sunday that one of Segue's subcontractors, R. Bros. Inc., was responsible for the waterproofing work on the Library Gardens balconies. The Chronicle said both Segue and R. Bros. were sued after dry rot showed up in balconies at a Millbrae condo development just a year after construction on the project was finished.
Dry rot is the product of a fungus that takes hold in saturated wood and causes it to deteriorate. The California Building Code calls for a number of measures -- including waterproofing and drainage -- to prevent wood from getting wet. Berkeley's initial inspection indicated that at least some of the required measures -- for instance, a waterproof membrane designed to protect the wooden joists from exposure -- were in place.
Alex Emslie of KQED News contributed to this report.
Vinnee Tong of KQED News contributed to this report.
Bay City News contributed to this report.
This report was updated to include a statement from the Alameda County District Attorney's Office and attorney David Anderson.