Get the latest from TODAY

Sign up for our newsletter
By Emily Sher

Troops at the Brooke Army Medical Center in San Antonio, Texas got a special surprise after a screening of "American Sniper" on Jan. 14: a visit from Bradley Cooper.

As nearly 260 service members watched Cooper play Navy SEAL Chris Kyle — the most lethal sniper in U.S. military history — the actor secretly made rounds through the hospital visiting patients and wounded soldiers. The crowd erupted in applause when Cooper suddenly entered the auditorium at the film's end, according to the BAMC press release.

And Cooper didn't come alone. Special guests like Kyle's father Wayne and two veterans who appeared in the movie, Bryan Anderson and Jacob Schick, joined him for a question-and-answer session.

"I know when Bradley walked in you were all cheering wildly for him, but it's us who needs to be cheering for you all," Wayne Kyle said. His son Chris, whose story served as the basis for the film and book of the same name, was tragically shot and killed in February 2013 at a shooting range after serving four tours in Iraq and receiving several commendations for acts of heroism.

In answer to how he prepared for the role, Cooper said he studied the intricacies of military weapons and added bulk to his frame.

"Making this movie was a life-changing experience," he said, according to BAMC. "I was terrified when I started. I didn't know if I could actually get to a place where I would believe that I was Chris."

For at least one Marine in the audience, Cooper did the part justice. "I feel like you are one of my brothers," he said in a tearful response. "I think you did really well and I just want to say thank you."

Cooper delivered an additional message to all service members in a video interview with All Hands magazine on Jan 15.