Congressman Sean Casten with his daughters Gwen, left, and Audrey, walk through the U.S. Capitol Building on Jan. 4, 2019. (Photo: Chicago Tribune via Getty Images)
Congressman Sean Casten with his daughters Gwen, left, and Audrey, walk through the U.S. Capitol Building on Jan. 4, 2019. (Photo: Chicago Tribune via Getty Images)

Sean Casten and his daughters walked through the U.S. Capitol Building in January. The photo was taken by the Chicago Tribune.

Gwen Casten died in her sleep, according to Sean Casten, her father.

Gwen died that morning, according to the congressman's office. According to the Chicago Tribune, the teen was found dead in a home in suburban Chicago.

Casten said there were no words to describe the hole in his heart when a child died.

She went out with some friends for a few hours after we had dinner. He said that when she got home, she said goodnight to him and Kara, and that she didn't wake up on Monday.

We don't know what happened to her, but it was peaceful. savor the moments you have with your family is the only lesson we can take from that. We want to make a difference. We want to believe in the future. We can't control our present.

We are grateful to all who have reached out with thoughts, condolences and help. To all asking what they can do, we ask only that you live your lives as Gwen lived hers. pic.twitter.com/AdQTpzsnTP

— Rep. Sean Casten (@RepCasten) June 15, 2022

According to Casten, his daughter was looking forward to her freshman year at the University of Vermont, where she would study environmental science.

She was a big fan of music and activism. She was a member of the jazz band, the wind ensemble and the pit orchestra at the high school.

Gwen was inspired to create an Empowerment Club at her high school which focused on everything from gun violence prevention to environmental protection to LGBTQ allyship.

Gwen co-founded the Illinois chapter of March For Our Lives, the student-led movement that fights to end gun violence, according to her biography.

The note was signed by Casten, his wife, and their daughter.

The article was first published on HuffPost.