Replying to a message of Paul Ranson to David N. Barnett:

 PR> From: "Paul Ranson" 

 PR> I think there's an element of urban myth there. What could be done
 PR> about it?

Since the Brits knew the target well in advance of the raid, they could
have evacuated the city.  They also could have had the RAF muster extra
fighters in the area.  They did neither.

Check David Kahn's 'The Codebreakers' (MacMillan, 1966), I think there's
something in there about it.  It is NOT an urban legend.

---