You know, the ones that were mercilessly parodied by sites such as unready.org (which sadly seems to no longer exist). Does anyone know where I can find the original images? Are they still around or has the US government pulled them out of embarrassment?
I’m guessing you’re referring to the PDF files like “Biological Threat” and “Chemical Threat” from Ready.gov.
You can give sites you know the URL of a try in Internet Archive: Digital Library of Free & Borrowable Books, Movies, Music & Wayback Machine. You can do a search on the site also if you know the name, but not the URL.
Guess I found those parodies !
http://nickm.com/misc/unready/
The original diagrams seemed quite useless indeed.
And, omg, in the instruction diagram for ‘chemical attack’ they repetitively use a ‘biohazard’ symbol.
They’re the ones! I looked on ready.gov but didn’t manage to find them. Thanks MEBuckner! And thanks for finding the parodies too, Oukile 
And yes, I also found the original diagrams pretty pointless and loved Unready when it was still around.
Here are the originals: go to
http://www.ready.gov/america/beinformed/
Now on the green menu to the left, you can select ‘biological threat’, ‘nuclear threat’, etc… you get the corresponding pages, and some of them contain a link to the ‘visual guide’
And, my god, even the articles they give are ridiculous. Look at ‘fire’, they don’t mention what to do in case the escape route is full of fumes (don’t ever walk in the fumes, barriace). In ‘extreme heat’, i.e. heat wave, they don’t mention the fundamental thing to do: keep hydrated and make sure that old people who don’t feel thrist drink enough. ‘Earthquake’: they say nothing about what to do when an earthquake actually happens.
Thanks for posting the parodies – I had never seen that version. They are hilarious.
I remember this version being circulated quite a bit a while back.