At 2 a.m. on Sept. 21, Typhoon Roke, the 15th and biggest tropical storm yet to assault Japan this year, was over the Pacific 200 km south of Shikoku making its way slowly and ominously westward toward the main island of Honshu.

In Tokyo, where an atmosphere of public calm had reigned before the storm, Tetsuya Shimazu — who is in charge of disaster prevention in the Tokyo Metropolitan Government's rivers department — was already on high alert in his 22nd-floor office in Building No. 2 of TMG's twin towers in Shinjuku.

With him were many other TMG staff, some of whom had been summoned that night from the nearby public housing where they are billeted apart from their families whenever disaster looms or has struck the city — whether due to typhoons, earthquakes, tsunami or anything else.