One of the 16 jet-engine fans that keeps Vancouver's Olympic stadium roof aloft exploded last Wednesday, according to 24 hours sources.

Rapid air pressure drops occurred at B.C. Place Stadium Feb. 17 around 8 p.m. and again Feb. 18 at 5:10 a.m. One source said the protective screen for the shrapnel-covered industrial fan room was blown out. Another fan was already out of service for maintenance.

Stadium general manager Howard Crosley said a support rod "worked itself into the fan blades and that's what caused it to fail."

"The building control system sent out an alarm and automatically reacted to the subsequent pressure drop," Crosley said. "The pressure drop was noticeable because of the response time of the pneumatic system, but the roof was not in peril."

Crosley said two to three fans are currently used to inflate the fabric roof. There were also rapid pressure drops on Nov. 16 and 17, Dec. 19 and Feb. 10. Workers manually opened air dampers on Dec. 17 to enable the snow-melting system.

The 2010 Winter Olympics open at B.C. Place in less than a year. The taxpayer-owned stadium's air-supported fabric roof will be replaced with a retractable system by 2011 as part of a $365-million overhaul that began last summer.

Bob Mackin writes for Vancouver 24 hours and appears regularly on the Hook.