Work started this week on raising the steel arches of Santiago Calatrava's design for the refurbishment of the Olympic stadium in Athens. The start of the installation of the 18,000-tonne roof came days before the International Olympic Committee said Greece would be ready to host the Games. Denis Oswald, the IOC's chief inspector, said on Wednesday: "We had doubts about some of the venues and infrastructure, but I am very happy to report these have all disappeared – we know everything will be delivered on time."