Andy Irvine (Warwick bass dude and all-round nice chap) has posted about it on his facebook page, so sadly I suspect it's all too real:
Today is a very sad day for the bass guitar world and for me particularly as a personal hero and one of the greatest players of all time has passed - Louis "Thunder Thumbs" Johnson. His pioneering work developing the funky bass, slap bass and booty shaking dance grooves found him in the top class of all time. His playing with The Brothers Johnson defined the era and set the musicianship bar high with the deepest of pocket groves and virtuoso blistering slap bass. Later he became the go to player for legendary composer/producer Quincy Jones and played on dozens of hits including many iconic bass driven cuts with Michael Jackson. I was given his Star Licks VHS tape in 1983 and wore it out, watching it thousands of times and learning from him what funk groove and slap bass is all about. Later in my career I began to teach and present my own educational workshops and clinics. I've mentioned him at every single one I've ever done and also in my book. I list him in my top 3 influences of my entire playing journey thus far. In recent years I was able to connect with him and formed a great pen pal relationship. I talked with him regularly and continued benefitting from his knowledge, kindness and spirit. He was a warm and delightful man. My deepest condolences to his family.
https://www.facebook.com/bassistandy