U.S. Rep. Sean Casten's 17-year-old daughter, Gwen, dies

Gwen Casten, the 17-year-old daughter of Illinois Rep. Sean Casten, has died, the congressman's office confirmed in a tweet Monday.

"This morning, Congressman Casten's beloved daughter, Gwen (17), passed away," the tweet from the Democrat, elected in 2018, read. "The Casten family requests privacy, and we will be issuing no further comment during this heartbreaking time."

Casten's office did not provide any details on the cause of death.

The teenager had recently appeared in a campaign video supporting her father's bid for a third term in Congress.

In the video released earlier this month, she spoke of how turning 18 would be a "big year" filled with "lots of milestones," including "voting for the first time. But not just for anyone."

"Sean Casten. My congressman. But I call him dad," she said in the video, in which she championed her father's efforts on new gun laws and protecting abortion access.

Casten, a Democrat, represents Illinois' 6th Congressional District. According to his campaign website, he was first elected in 2018 and was the first Democrat to represent the district in nearly 50 years.