The above come from an Associated Press story about the National Institute of Standards and Technology's just released report on Joplin tornado. It is 429 pages long. I read the pertinent parts yesterday. It comes to the same conclusions as When the Sirens Were Silent.
One of the reason there was a "lack of awareness" the tornado was approach was because the tornado sirens were silent during that time.
Rather than spend hours reading a very dense and technical report, if you want to know what went wrong in Joplin, you can go to the library and borrow a copy of the print version or purchase (just $2.99) the very easy to read Sirens. It is also available for Nook and Amazon's free Cloud Reader. It is about 60 pages long.