"This Is Us" fans are on the edge of their seats as even actors in the show have teased about the truth behind a character's death that will be revealed in upcoming episodes. Will viewers finally find out the truth about Jack Pearson's death soon?

According to US Magazine, Jack Pearson (Milo Ventimiglia) died when Kevin (Justin Hartley), Kate (Chrissy Metz), and Randall (Sterling K. Brown) are teenagers. In the present, Kate is still so distraught over his death that she can't bring herself to discuss it. Hartley said, "You'll never guess it." He continued, "It's unexpected and it's extremely heartbreaking and sad and deep and moving and, ugh, it's painful. It's painful. It'll stay with you."

Ever since it was revealed that Jack died, fans have started theorizing about the cause of his death. Hartley reveals that he reads some of the theories, but no one has gotten it right yet. This isn't the only tearjerker in "This Is Us": in the episode called "Memphis," Randall's biological father William Hill (Ron Cephas Jones) also dies.

Series creator Dan Fogelman has also talked about William's death. In an interview with Entertainment Weekly, Fogelman revealed that "Memphis" was planned as the last episode where viewers will see William alive.

Fogelman also talked about how the right thing to do wasn't to give William longer to live. He shared, "First and foremost, it felt to me like life doesn't play out all the time like a TV show, you know? The characters in your life don't die during the season finales all the time. And they don't always die exactly in a rhythm of how you expect it to happen or when or where, so that was part of the thinking."

He adds, "I lost my mom eight years ago in a very traumatic and unexpected way. She died during a surgery that wasn't supposed to be life-threatening in that way..." The series creator also talked about how his mother's death shaped the direction of "This Is Us." Despite losing Jack, he remains "in the picture" for the family he left behind.

Like Jack, Fogelman also teased that William will still show up in upcoming episodes of "This Is Us" via flashbacks. He even confirmed that William will "remain a big part of the show."