On June 9th, 1972 Rapid City, South Dakota suffered through one of the worst flash floods in United States history. More than 230 people drowned when a tsunami like wall of water came roaring out of the Black Hills and crashed into towns downstream. Forty years later, survivors tell their stories, and new scientific studies on the frequency of flash flooding underline the dangers of rebuilding in the flash flood plain.
Here is the radio documentary on the 40th anniversary of the 1972 flood submitted for the 2013 RTNDA Murrow Awards. It first aired on June 7th, 2012 and runs about a half hour.
Also here is a link to SDPB’s more comprehensive coverage of the 40th anniversary of the 1972 flood. This is not part of the official entry, it's only included here as a reference to show the breadth of coverage on this topic.