Kelly Clarkson brings "American Idol" judges to tears

It all came full circle when Kelly Clarkson returned to "American Idol" on Thursday, the show that made her a household name when she won the first season of the show.

The pregnant singer performed her song "Piece by Piece," which is about her relationship with her father and also a tribute to her husband, Brandon Blackstock. Clarkson told Gayle King on CBS This Morning in November, "It was a vulnerable song ... saying yes, I did have help and somebody helped me back together. I think a lot of people will view that as weakness, but I think it's a strength to trust someone."

The pop star got so choked up while she sang that she even paused and whispered, "Sorry," in the middle of the song as tears streamed down judge Keith Urban's face. Jennifer Lopez was also seen crying.

After she finished, the audience cheered her name and the judges all stood and applauded.

Host Ryan Seacrest approached Clarkson and said, "You had us all in tears."

She wiped tears from her face and said, "I'm sorry. I can't believe it's the last season. I'm really sorry I just bawled. I'm actually quite proud I made it this far." The show, which premiered in 2002, is wrapping after this season.

Clarkson chalked up the tears to her hormones; the singer is pregnant with a boy.

The song is an emotional one for Clarkson. She cried singing the same song at a concert in Los Angeles in August, when she announced, "I'm totally pregnant."

Watch the video below.

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