I’ve been on a video shoot this morning, so I haven’t read much of anything about the convention center collapse in Pittsburgh. But from what I’ve read so far here here and here, the David L. Lawrence Convention Center seems to be turning into Pittsburgh’s version of Boston’s John Hancock Tower.
The building’s most dangerous and conspicuous flaw was its faulty glass windows. Entire 4′ x 11′, 500 lb (1.2×3.4 m, 227 kg) windowpanes detached from the building and crashed to the sidewalk hundreds of feet below. Police closed off surrounding streets whenever winds reached 45 mph (72 km/h). According to the Boston Globe, MIT built a scale model of the entire Back Bay in its Wright Brothers Wind Tunnel to identify the problem. The exact cause of the malfunction was never revealed due to a legal settlement and gag order. Most now diagnose the problem as a combination of the double-paned glass construction method, and the pressure differentials between the inside and outside air. [citation]
At least it was cheaper and didn’t take as long as the John Hancock. And our deathtrap is much prettier.