Torn Convention Center Roof Still Mystery : Storm: Officials say they don’t know why panels made to stand 100-m.p.h. winds failed in rainstorm.

Officials said Wednesday that they still do not know what caused a giant Teflon-coated panel stretching over the San Diego Convention Center to tear apart during a March rainstorm and are not sure when it will be replaced.

Dan Wilkens, spokesman for the San Diego Unified Port District, said the manufacturer of the panel is now performing sophisticated computer tests to learn what caused the panel, 25 feet wide and 330 feet long, to tear apart. The panel, designed to withstand winds of up to 100 m.p.h., fell apart Feb. 28 in a rainstorm accompanied by 27-to-35 m.p.h. winds.

The tear has been patched, but it is hoped that permanent repairs will be done in time for next winter’s storms, Wilkens said.

The damaged panel stretches over a special events area atop the convention center. Longer than a football field, the panel covers four huge ventilation holes on the center’s main tent roof and is designed to keep rain out of the special events area. Convention center spokeswoman Donna Alm said the area is popular with many groups.

“As we go into the summer months the repairs probably won’t be quite as pressing,” Wilkens said. “But, as you move into the fall and winter, it can be a problem. . . . I’m hoping we’ll have it done before the rainy season.”

Birdair, a Buffalo, N.Y. company that manufactured the sail, is doing computer tests to find the cause of the panel’s collapse. Company officials do not know how long the tests will take, said Wilkens.

“They still don’t know what happened . . . . The game plan is for Birdair to figure out why the panel came down. It’s important that they know this, because we don’t want to put up a replacement and then have it come right back down under the same atmospheric conditions. But the conditions at the time (of the panel’s collapse) didn’t seem all that unusual,” Wilkens said.

Alm put the combined cost for the sail and Convention Center’s tent roof at $1.6 million. The cost of the entire tent roof over the center and the special events area it covers was $6 million, she added.

Wilkens said that Port District officials do not know how much the repairs will cost. Although liability for the damaged sail has not been established, Wilkens said the port’s position is that the panel was still under the manufacturer’s 10-year warranty.

The Birdair official supervising the tests of the fabric could not be reached for comment Wednesday.

The Convention Center’s main roof structure was not damaged in the March storm and is not in danger of collapsing, officials said. The special events area was re-opened when an engineering inspection found no structural damage to the roof.

However, during the late winter storms in March, which brought several inches of rain, one event had to be moved to the main convention area, Alm said.

“That was the only reception that had to be relocated. Fortunately, the other receptions scheduled for that area in March fell on days when the rain wasn’t coming down. Business hasn’t been impacted yet,” she said.

But Convention Center officials are keeping their fingers crossed that it does not rain next week. Alm said local auto dealers have booked the entire building for an auto show from April 24 to April 28.

“That means that they’ve booked the special events area, too. They told us they want to carpet the area for the show, which means they’ll be installing 100,000 square feet of carpeting,” Alm said.