It’s hard to tell what’s real and what’s fake on a simulated battlefield in San Diego, California.

Owner Kit Lavell is a Vietnam vet and calls the training environment "hyper-realistic." He turned a movie set into a mock battlefield and now prepares thousands of U.S. servicemen and women for combat using real amputees as actors.

"The individuals who are going through the training here are not expecting to see an amputee," says Lavell. "And so the shock effect of seeing that happen is priceless."

We’ll take you inside this training facility Monday in the 5 p.m. ET hour on Evening Express. You'll get to hear from the trainees and amputee actors about this training simulation's emotional impact.

Watch Evening Express 5-7 p.m. ET on HLN.