It was a summer day in June of 1979 when then-8-year-old Sara Evans was faced with a decision: Should she cross that busy street in front of her family’s farmhouse in small-town Missouri? Should she go get the mail from the mailbox, or should she listen to how her parents warned her not to? When all was said and done, the girl with the strong voice and even stronger will decided to cross the street.

It was a decision that would change her entire life.

"The last thing I remember was a flash of blue," Evans writes in her new memoir, Born to Fly, exclusively excerpted in People magazine. "I woke up in a cold room and then came the pain. I was terrified. Both of my legs were in casts. My mom told me that when the car struck me, I landed 80 feet off the road. When they found me, I was curled up in a ball with my left leg mangled and twisted and almost severed in two. They all thought I was dead."

The memoir, released Sept. 8, recounts those awful days following the accident, as Evans would end up spending "six agonizing weeks" in the hospital undergoing a slew of excruciating medical procedures.

“Since my concussion was so serious, they were afraid to put me under anesthesia,” remembers Evans in the revealing book. “They would numb my leg and use a hand drill to get the pin into my knee. I remember the nurses holding me down. Every time Dr. Breedlove brought the drill close, I cried out, 'Wait!' Imagine someone drilling into your leg while you're wide awake. Dr. Breedlove finally just told the nurses to hold me down so he could get it over with."

It was those experiences that the 49-year-old now says led to a life in which she has battled with everything from PTSD to anxiety to claustrophobia at various points.

But things have gotten better.

"I still struggle," she says. "But I'm so grateful for every second of this life."

Enter your number to get our free mobile app

Country Music's 30 Most Powerful Women Ever: