Jill Morgenthaler, a retired U.S. Army colonel who was Illinois’ homeland security chief under former Gov. Rod Blagojevich and once ran as a Democratic against U.S. Rep. Peter Roskam, died in a scuba diving accident over the weekend in Central America, according to friends.

Ms. Morgenthaler, who was awarded the Bronze Star for her service in Iraq, also was an author and a popular public speaker.

She was “a true American hero who touched thousands of women through her leadership book,” according to a Facebook post by her brother Jeffrey Morgenthaler, speaking of her work “The Courage to Take Command.”

“She came into politics as a political outsider who had amazing experience in the real world, and her enthusiasm inspired women. Her strength gave them the courage to believe that they could do anything,” said former spokeswoman Kitty Kurth, who confirmed her death.

After writing the book and becoming a speaker, she “just never stopped achieving her dreams and helping other people understand they could achieve their dreams as well,” Kurth said. “And she was a badass. She was a badass with a good heart.”

Ms. Morgenthaler grew up in different spots around the country as a daughter of a Marine. She lived in the northwest suburbs with her husband, Kurth said. She is also survived by two children.