Mike Knudsen wrote:

It's a pretty well known story (maybe even true) that the Brits knew the German
air raid was coming to Coventry (by breaking the code and/or watching the
bombers on radar), several hours in advance, but deliberately did not warn any
civil defense or firefighters in Coventry, for fear of tipping the Krauts that
we were reading their mail.

So apparently Churchill was willing to sacrifce Brit lives, and not jsut US
sailors, to hide the code breaking. --Mike K.

It may be "a pretty well known story", but it may also be an urban
legend". There are indications each way, and I seem to recall having
seen it exposed as an urban legend.

--
"We have captured lightning and used it to teach sand how to think."