I was sorry to hear this news. Apparently he had a stroke two weeks ago and has been struggling since that time. "Dutch" was one of my favorite writers.
http://www.cnn.com/2013/08/20/showbiz/elmore-leonard-obit/index.html
http://www.cnn.com/2013/08/20/showbiz/elmore-leonard-obit/index.html