VANCOUVER - A combination of natural causes and human error led to the roof collapsing at B.C. Place stadium, general manager Howard Crosley said Friday.
He said a preliminary report showed weakened fabric, a rapid pressurization of the roof and heavy wind conditions caused the structure to tear.
A B.C. Place employee quickly increased the pressure on the roof last Friday after staff noticed it was slightly inverted during a heavy wind and sleet storm.
At the same time, another person turned on an additional eight fans to keep the air-supported roof inflated.
"The staff reacted as they're trained to do," Crosley said. "Which is, when they noticed a depressurization in the facility, to apply pressure. The mistake that was made was that two people were operating the controls at the same time."
Engineer Kris Hamilton, who is conducting a report of the incident, said there was three times more pressure on the roof than there was supposed to be.
Despite regular inspection of the roof, staff did not catch a weak area in the Teflon-coated material.
"We can't tell the age of the damage, it is unlikely that it happened in a year," said Hamilton.
"Only a very, very detailed inspection that suspected such a damage could have actually found it."
He said he had never seen the combination of factors that led to Friday's collapse.
"We have not seen any fabric structure prior fail due to such damage of the fabric," Hamilton said.
A final report of the incident is expected to be complete by the end of the month.
On Friday, a new panel was being installed. It was estimated to be in place within two days.
Smaller additional patches that tore after the roof collapsed are also being repaired. The roof's re-inflation is expected next week.
B.C. Place officials said they are confident the 60,000-seat stadium will re-open in time for the next scheduled event on Jan. 23.
Crosley said insurance will cover the damage but the stadium will pay the deductible, which was estimated to be $75,000. He said the money will come from the general operations fund.
The stadium will host the opening and closing ceremonies of the 2010 Winter Games.
