New forensic tests ordered on timber in Berkeley balcony
Fresh forensic tests have been ordered by US authorities on the timber balcony supports that failed at a San Francisco apartment complex, causing six students to fall to their deaths.
The timber support beams were found to be severely dry-rotted on the fourth storey balcony of the Library Gardens building in Berkeley despite the fact it was only built in 2007.
Six students, five Irish and one American, died in the June 16 tragedy.
Seven students were badly injured when they fell onto the concrete pavement below. A number of them remain in hospital.
It has now emerged that Alameda County District-Attorney Nancy O'Malley has ordered a full forensic engineering analysis of the eight timber support beams.
The beams were machined softwood which had been wrapped in a special waterproof membrane.
However, Ms O'Malley's 60-strong staff will now determine if the timber used as balcony joists was ever suitable for such a load-bearing role.
The investigation is also focused on whether the critical waterproof membrane was somehow damaged during installation - allowing water to leak around the timbers and trigger dry rot.
The City of Berkeley confirmed the Library Gardens apartment complex at 2020 Kittredge Street had third and fourth floor balconies designed to withstand a weight of 45kg (100lb) per square foot - substantially more than the California building regulation which requires a load factor of 28kg (60lb) per square foot.
Both the builder, Segue Construction, and the waterproofing contractor, R. Bros, are now co-operating with the three separate investigations.
Civil and criminal investigations are being carried out by Ms O'Malley while a third probe is being conducted by the Contractors State License Board (CSLB), which oversees more than 300,000 construction contractors in California.
CSLB has admitted it was totally unaware the construction firm that developed the Berkeley complex had paid out €23m ($26.5m) in lawsuit settlements in just six years.
In two cases, in San Jose and Millbrae, the damage claims involved water leaks on timber balconies. Segue insisted those lawsuits were totally unrelated to the Berkeley tragedy.
The firm obtained an operator licence from CSLB in 1992 and renewed it last year.
It remains unclear what action, if any, will result from the triple investigation.
However, Ms O'Malley's criminal investigation does have the power to initiate charges of up to involuntary manslaughter.
The probe could take several months.