CHICAGO (CBS) — Three Chicago high school Junior ROTC students have returned home from what one called the “trip of a lifetime” – an all-expenses-paid trip to the site of the D-Day invasion of Europe in World War II.

For Curie High School senior Aisolis Ramos, it started with an essay: why she wanted to go to France and the beaches of Normandy.

“In ROTC, they teach us about integrity. It’s the way you carry yourself and you have to be honest,” she said. “So, in my essay, I said I don’t know much about the D-Day invasion. I’m not going to say I do. No.”

Ramos said she wanted to learn about D-Day. She was one of three cadets in the city to be chosen for the trip to Normandy.

Her mother, Rosalba Sandoval, said she couldn’t believe it at first.

“Once she told me she won, I said, ‘No you didn’t.’” She’s like, ‘Yes, I did,’” Sandoval said.

Ramos studied some history, and looked at some old photographs before she went.

“All those are black and white pictures, and now you’re standing there. You’re standing in the sand, and you see the ocean, and everything around you, and you can close your eyes and just imagine the missiles going down and everyone running, and soldiers dead on the ground,” she said.

The First Division Museum at Cantigny paid for the trip for the three students.