eggs and baskets
@AC 'serves the manufacturers right'. Tech industries call it clustering, think about the pool of talent all in one place (no flood pun intended). Silicon valley is of course one of the better known cases of clustering.....and it sits on the Hayward fault. Earthquake city.
Talking about eggs in one basket....try London, as this is also on a FLOOD PLAIN http://maps.environment-agency.gov.uk/wiyby/wiybyController?x=531500.0&y=181500.0&topic=floodmap&ep=map&scale=3&location=London,%20City%20of%20London&lang=_e&layerGroups=default&textonly=off#x=536064&y=178206&lg=1,&scale=7