A 22-year-old Torrance woman shot at the Route 91 Harvest festival in Las Vegas has died, according to friends who along with her family desperately scrambled Monday to learn her fate.

Christiana Duarte was watching country music singer Jason Aldean perform with her brother’s girlfriend, Ariel Romero of Bellflower, when Stephen Craig Paddock fired indiscriminately into the crowd from an upper-floor room at the Mandalay Bay Hotel and Casino that overlooked the outdoor event.

Paddock killed 59 people in what is the largest mass shooting in modern U.S. history. More than 22,000 people ducked and fled as rapid-fire gunshots rained on the concert crowd after 10 p.m.

Romero, among more than 515 people injured in the attack, was shot in the face and is hospitalized with a fractured jaw.

“The gunshot entered her cheek and exited her neck,” said her aunt, Perla Arellano. “She’s in stable condition.”

Family members spent Monday scouring hospitals and police stations for Duarte. Friends reported that she was found at about 4 p.m. in critical condition, but later said that was not true. Her death was confirmed late Monday night, friends said.

The pair was having a great time in Las Vegas with their family on a weekend getaway before the shooting occurred. Duarte posted Snapchat messages swimming in a hotel pool and told friends the festival was “super fun,” said her close friend, Maddie Noble.

Noble was texting with Duarte until she stopped responding at about 10 p.m., when the shooting erupted.

As soon as Noble heard news reports of the shooting, she fired off texts to her childhood friend: “What’s happening? Are you OK?”

There was no answer.

Romero is the girlfriend of Duarte’s brother, Mikey Duarte, who is in Las Vegas with family members looking for Christiana.

“We’re searching for my sister,” Mikey Duarte said in a text to Noble on Monday afternoon. “Pray hard please. I need my little sister. Her and Ariel are all I’ve really got.”

In the aftermath of the shooting, police found Duarte’s cellphone, credit cards and identification and returned it to her family members, but had no information about her whereabouts.

Duarte graduated from South High School in Torrance and, in May, from the University of Arizona, where she was a member of the Sigma Kappa sorority. She worked as a fan-services associate for the Los Angeles Kings.

Romero’s phone also was lost in the chaos. But she wrote her mother’s phone number on her hand before losing consciousness so rescue workers could notify her, Arellano said.

“My sister knew my niece was at the event and kept calling her phone worried,” Arellano said. “Finally, some guy answered and said: ‘I found this phone.’ ”

Soon after, Romero’s mother got the call that her daughter had been hospitalized with a gunshot wound.

Romero recently graduated from Loyola Marymount University in Westchester and is pursuing a law degree at Chapman University.