Don Mischer, an award-winning producer and director who brought calmness and meticulous preparation to live television extravaganzas like awards shows, Olympic opening ceremonies, Super Bowl halftime performances and the 2004 Democratic National Convention, died on April 11 in Los Angeles. He was 85.

His death was announced by a spokeswoman for his family, who did not cite a cause or specify where in Los Angeles he died.

Mr. Mischer’s most recent project, on April 5, was serving as the executive producer of the star-studded Breakthrough Prize award ceremony, which honors scientists and is sometimes called the Oscars of science. In the days before the event, he told the trade news website Deadline that he would retire after the show.

When Mr. Mischer was hired as the executive producer of NBC’s telecast of the opening ceremony of the 1996 Summer Olympics at Centennial Olympic Stadium (later Turner Field) in Atlanta, he was entrusted with a secret known to only four other people: The Olympic cauldron would be lit by Muhammad Ali, the former heavyweight champion.

As the ceremony neared its conclusion, Ali dramatically stepped out of the shadows, dressed in white, his body trembling from Parkinson’s disease. He took the Olympic torch from Janet Evans, an Olympic gold medal-winning swimmer, showed it to the crowd and ignited the cauldron.