Chasco, 20, and her friends had just started running away from the gunshots fired from across the Las Vegas Strip when she fell to the ground.
“That’s when I got shot and was on the ground,” said Chasco, who was hit in the back.
A University of Nevada at Reno student, she was one of more than 500 injured concertgoers in what became the worst mass shooting in modern U.S. history.
Stephen Paddock, a 64-year-old resident of Mesquite, Nevada, is accused by police of opening fire on the crowd at the music festival from the 32nd floor of the Mandalay Bay Resort and Casino on Sunday night, killing 58 people.
Chasco recalled that friends pulled her to a fence outside the concert venue after she was shot.
“Then we ran into MGM [hotel] and we heard more rounds inside so we ran back out,” she told ABC News. “During this time, I was on the phone with my parents, just telling them what was going on, making sure they were OK so they weren’t worrying or anything.”
By chance she ran into an EMT who was visiting Las Vegas. The EMT got on the phone with her father and reassured him he would call 911.
Chasco, who was helped by more first responders, was eventually put into an ambulance. She sat alongside a husband and wife who had both been shot and a person on a gurney who she said died on the way to the hospital.
“I ended up being in the hospital for four or five hours, and I was … very fortunate,” Chasco said through tears. “Just because I still have the bullet in my back, but it was lodged very nicely so it didn’t hit any nerves or break any bones.”
She recalled being helped by good Samaritans throughout the ordeal. A nightclub security guard who showed up at the hospital to help stayed with her and told her to make sure she reached out to him on Facebook so he would know she is OK.
Another stranger found Chasco’s abandoned cellphone at the concert venue and returned it to her.
Her parents drove to Las Vegas from their home in California in seven hours — normally it's a 10-hour drive — to be by her side.
Chasco said she tried to remain calm in the hospital amid the trauma situation as hundreds of victims were taken to hospitals and medical staff and volunteers struggled to meet their needs.
“I didn’t want to be one of them who was just crying and screaming and freaking out, so I just tried to really keep a level head,” she said. “I remember the first nurse who I saw, she was very nervous, and so I asked her, ‘How are you doing tonight? Did you just come in?’”
She explained, “I just wanted to kind of keep a regular conversation going among all of the craziness around us.”
Chasco was released from the hospital and is recovering. The boyfriend of a friend who attended the concert with her was killed in the shooting.
“I’m a very strong believer that everything happens for a reason,” she said. “I know there’s not much of a reason that something like this could have happened, but you could always find something to hold on to, at least one positive aspect in this.”
She continued, “I just keep holding on to the fact that I do have a bullet in my back still but I’m walking and I’m talking, and that’s obviously something that I’m so grateful for right now.”
ABC News’ Janet Weinstein and Courtney Condron contributed to this report.