Updated: Friday, Sept. 21, 2018 -- 2:21 p.m. ET

Fifty-eight people were killed and more than 850 were injured in a mass shooting on Sunday (Oct. 1) at the Route 91 Harvest music festival in Las Vegas. The incident is being described as the deadliest mass shooting in modern U.S. history.

According to the L.A. Times, Jason Aldean was performing the fifth song of his closing set when the gunman Stephen Paddock, 64, started firing from the 32nd floor of the Mandalay Bay hotel toward the festival across the street. Aldean and his band were immediately pulled off the stage when shots rang out, and they escaped injury.

Authorities say the suspect, Paddock, was discovered dead in his room at the Mandalay Bay hotel, and that he acted alone. A person of interest who is believed to be Paddock's companion Marilou Danley, 62, has been cleared by police of any involvement in the shooting. She was out of the country when the incident occurred.

President Donald Trump expressed his sympathies for the victims via Twitter.

The crowd began to stampede as a result of the chaos and the entire area of the Las Vegas Strip was put on lock down. Some flights at the McCarran International Airport were diverted in the wake of the shootings and parts of I-15 near the Strip were also shut down.

Many artists at the festival sought shelter backstage and have been communicating with fans on social media. It was a sold-out event with more than 22,000 tickets sold for all three days.

A performance by Jake Owen preceded Aldean's set.

Chris Young said he could hear the gunfire from his trailer behind the stage.

This story is developing.