Especially when Dianne Feinstein's husband owned large portions of Tutor Perini. TPC were the guys who tried to pass off the low-quality steel rails they installed as equivalent to what was requested in the Central Subway.

My personal hypothesis is that Americans get very defensive about this because there's a cultural resistance to being the guy who got fooled, so many of us will invent reasons that fall down really fast like "SF is an old city with lots of underground things." or "SF is in an earthquake zone" or (my new favourite) "Liquefaction", etc. etc.