Tears Flow When Kids Serenade Their Teacher Fighting Cancer

These kids made their teacher cry for all the right reasons.

— -- Sometimes students drive their teachers to tears for all the wrong reasons.

But in this case, these kids gave Adriana Lopez all the right reasons to cry.

The PS22 chorus from the largest public elementary school in Staten Island, New York -- made up of 65 fifth-graders -- serenaded Lopez, who is undergoing chemotherapy for cancer.

"Even on days when she was sick and fatigued, she would bring herself to work and give her everything to her students," said Breinberg. "She is a beautiful and inspiring person and no one deserves such a tribute more than she."

Lopez could not be reached for comment by ABC News.

"The kids were very emotional while practicing the song, lots of tears, they're very sensitive, very soulful little people," Breinberg said. "Don't let their ages fool you. And they kept it together when she came in for the performance and showered her with hugs and flowers after it was over. It was a moment no one in the room will ever forget."