Angelina Jolie arrives on the red carpet at the world premiere of her film "Unbroken" at the State Theatre in Sydney
Angelina Jolie arrives on the red carpet at the world premiere of her film "Unbroken" at the State Theatre in Sydney November 17, 2014. The war drama, based on the life of World War Two American prisoner of war Louis Zamperini, was produced and directed by Jolie and filmed in Australia. Reuters/Jason Reed

Brad Pitt stepped in for wife Angelina Jolie at the "Unbroken" premiere in Los Angeles. The actress is reportedly suffering from chicken pox. His three kids Maddox, 13, Pax, 11, and Shiloh, 8, joined him at the red carpet event. The three boys looked dashing in black suits. Pitt's parents Jane Etta and William Alvin Pitt were also seen at the event in support of their daughter-in-law.

Jolie's illness was announced on last Friday. She posted a video message on YouTube saying that she is down with chickempox and will be unable to attend "Unbroken" premiere and the upcoming press events.

"I just wanted to be clear and honest about why I will be missing the Unbroken events in the next few days, which is that I found out last night that I have chicken pox. I will be home, itching and missing everyone, and I can't believe it because this film means so much to me," said Jolie in the video.

"Unbroken" is Jolie's second directorial venture. It charts the journey of a WWII Olympian Louis Zamperini who survives a plane crash and spends 47 days in a raft. The Japanese navy later takes him as the prisoner of war. The movie is based on the book by Laura Hillenbrand "Unbroken: A World War II Story of Survival, Resilience, and Redemption." English actor Jack O'Connell has portrayed Zamperini on the screen. The film is speculated to be a major award contender for this season. It has already scored four Critics' Choice nominations from the Broadcast Film Critics Association, including best picture and best director.

Meanwhile, Jolie thinks that though the film is a war drama, it is appropriate for her kids to watch. She said to E! Online that the film has got PG-13 certificate and her son Maddox falls in the prescribed age bracket. She even said that she wouldn't mind showing the film to her younger children as she thinks they understand the film. She finds them capable enough to differentiate between reality and fiction. "Unbroken" will release on Dec. 25 in U.S and on Dec. 26 in U.K. The film has already been released in Australia.