While today’s sleek skyscrapers filling urban landscapes seem to embody modern and cutting-edge design, it’s often not until after these mammoth structures are built that hidden design flaws rear their ugly heads, sometimes with rather dire consequences. In one particular case, these consequences included a building that was quite literally melting nearby cars. London’’s year-old 20 Fenchurch Street tower is a stunner, but the same curved glass that gives the 37-storey tower the nickname, “The Walkie Talkie,” also has a knack for concentrating sunlight. The result of which is a hot spot that melted part of a nearby black Jaguar XJ and cooked shampoo in a local barber shop. It’ has even been used to fry eggs. Such “death rays” are growing problem, thanks to a new generation of glass-sheathed buildings with radical computer-designed curves. Those curves reflect — and concentrate — light in ways that have been hard for designers and engineers to predict. At the recently held GPU...