Every big industrial company offers Wall Street a version of the same message. In a prospering and urbanising world, our machinery will be indispensable. Most relying on that vision have fallen well short. General Electric comes to mind. Until now the most successful exemplar has been Boeing, whose shares had almost quadrupled in the past three years on the back of expanding civil aviation in the developing world.

That success is threatened after two crashes of its next generation 737 Max single-aisle jet. The most recent was in Ethiopia on Saturday. This brought such terrible loss of life that a 7 per cent drop in market value, equivalent to $16bn, should be noted as an afterthought. Authorities in China and elsewhere wisely grounded the jet.

Boeing’s recent financial success is substantial. The sudden uncertainty around the 737 highlights how fragile that advantage is.