According to longtime agent Mark Bartelstein, Williams died in a Baton Rouge, La. area hospital.
Williams played nearly a decade in Cleveland after being drafted by the Cavaliers, and finished up his solid 13-year career in Phoenix and Dallas.
Per the NEOMG:
Williams was with the Cavs from 1986-93. He played on some highly successful and fondly remembered Cavs teams that made several extended playoff runs but could never quite make it to the NBA Finals. Included in that run was the loss to the Chicago Bulls in 1989, when Michael Jordan made “The Shot.” […] Those Cavs teams included Mark Price, Brad Daugherty, Larry Nance, Craig Ehlo and Ron Harper, among others.
“John loved playing in Cleveland,” said Bartelstein. “He played a few years after leaving the Cavs, but he always thought of himself as a Cavalier.” […] Williams was especially close to Lenny Wilkens, whom he called, “Coach Lenny.” Wilkins often used Williams as a sixth man because he liked an impact player coming off the bench.
The 6-foot-11 Williams was a completely unselfish player on the court. He loved to defend, block shots and set picks. In his nine seasons with the Cavs he averaged 13 points and 7.1 rebounds, shooting 48 percent. He could play any spot in the frontcourt. […] He played three seasons in Phoenix after being traded for Dan Majerle, then closed out his NBA career with Dallas in 1998-99.