Hannah was in the audience at the Route 91 Harvest music festival in Las Vegas on Oct. 1, 2017, when a man opened fire with an assault rifle from the 32nd floor of the Mandalay Bay hotel.
"I was hit before anyone really knew it was a shooting," Hannah said in an interview with ABC7.
Fifty-eight people were killed.
Hannah was among the 422 people wounded in the worst mass shooting in modern American history. She was critically injured in the shoulder and neck. The latter wound was the worst by far, damaging her spinal cord.
Many people offered prayers and support, including Miley Cyrus, who sent her a get-well video message. "I just wanted to let you know that I am thinking about you all the time," the pop singer said, "sending all good, healing, peaceful vibes to you and all your family and your friends."
After 17 days in the hospital, Hannah went home to La Verne. But she wasn't the same.
"Initially, when she came in, she was what we call a quadriplegic," said Dr. Justin Phillips of Pomona's Casa Colina Hospital and Centers for Healthcare. "So she was having difficulty moving her arms and her legs."
Hannah was in a wheelchair when she began her physical rehabilitation - unable to feed or dress herself and totally dependent on others for her care. She got to work, throwing herself into her recovery, with her family by her side.
"I think she's realizing how strong she is," said her mother, Loreto Hannah. "She wants her life back."
Katrina Hannah said it was "hard to remember how far I've come because I feel like I've still got a far ways to go, and it gets frustrating."
"But when I watch videos of me before, it's just like, wow," she added. "It's crazy that I've been able to do so much, I guess."
Over her year of recovery, Hannah has earned her MBA, been a bridesmaid and met with her rescuers.
When the going gets tough, she remembers how lucky she is just to be alive.
"For the people that passed that night, you know, you've got to keep pushing for the people that can't and didn't get the opportunity to fight like I did," she said.
Asked what she appreciated most, she responded: "I think, everything - my family, my friends. I think just life itself."
Hannah has suffered symptoms of post-traumatic stress disorder. Loud noises frighten her. She doesn't like crowds.
By choice, she has not undergone any psychotherapy. She says her physical therapy is helping her heart and her mind to heal, along with her limbs.
She hopes to return to work soon.