There was not a dry eye in the house Thursday night when Kelly Clarkson returned to the show that made her a star. The first ever "American Idol" winner dropped by the show to serve as a guest judge and sing her song "Piece by Piece." A couple of minutes into the song, the singer broke down and left current "American Idol" judges Keith Urban and Jennifer Lopez in tears.
"Piece by Piece" was a song that Clarkson wrote when she was pregnant with her daughter River, the singer told Glamour. The song is about the great father that her husband Brandon Blackstock is compared to her own father.
"It's not even sad tears; it's just such a beautiful thing that I have found," Clarkson said in a 2015 interview with the magazine. "I knew that this kind of love existed and that other people found it, but it's such a breathtaking moment. I'm going to just have to deaden myself and not listen to the words that I'm singing."
At the end of Clarkson's performance, the entire audience stood up to applaud her as Ryan Seacrest went over to comfort her.
"I'm pregnant, and it's nostalgic, and I can't believe it's the last season," Clarkson explained afterward.
This was not the first time that Clarkson has broken down during a performance of "Piece by Piece." The singer accidentally announced her second pregnancy in August during a concert at the Staples Center in Los Angeles, according to Entertainment Weekly.
"I was not planning on announcing this, but ... I'm totally pregnant," she told the crowd. "I'm having a really hard time."
Check out Clarkson's emotional performance on "American Idol" below:
