"It's rough. I just found out this morning," Smith told the Denver Post. "It was my mom who called and told me. The call came in at about 6:30."
Smith practiced Wednesday and still plans to play in the Super Bowl on Sunday, a source informed of his situation told NFL Media Insider Ian Rapoport.
Williams, 55, died after complications from recent heart surgery according to the Post. He had been in prison for more than 20 years after being sentenced to life in prison after a conviction for first-degree murder.
Smith played with Gary Kubiak and Wade Phillips in Houston, and was brought in as a free agent this season by the Broncos.