"There's no words in the world that can express how I feel right now," his son Bruce Jr. wrote on Facebook.
"I love you Daddy thank you for being awesome thank you for being loving thank you for being Who You Are I pray to God and we will meet again,"I love you Daddy R.I.H KING WILLIAMSON."
Born in Compton, California and raised singing gospel in church, Williamson joined The Temptations in 2006 and continued with the group through 2015. He sang soul music after leaving the group. He was set to perform on September 12 at a pay-per-view concert.
(Photo by Marc Broussely/Redferns)