Chris Young sent five tweets as the mass shooting at the 2017 Route 91 Harvest Festival unfolded late Sunday night (Oct. 1) and early Monday morning (Oct. 2). His tweets reveal his utter shock and dismay as the tragedy unfolded.

"I love you guys," he initially tweeted at 1:36AM ET, without any elaboration. He didn't follow up until 3:20AM ET, then saying, "Spent I don't know how long on the floor of a trailer behind the stage ... know multiple people are dead. Listening to that gunfire ..."

A minute later, Young admitted, "I'm literally shaking still." Then, at 4:06AM ET, a single word: "Why."

CNN reports that a single shooter, now identified as 64-year-old Stephen Paddock, opened fire from a hotel room on the crowd gathered outside the Mandalay Bay Resort and Casino at Las Vegas Village. He has been killed.

"I'm not gonna say anything else other than I'm lucky to be alive," Young's most recent tweet reads. "As are many others ... and so many people are gone ... this is heartbreaking."

At least 50 people are dead from and more than 500 were injured in the shooting.

Remembering the Route 91 Harvest Festival Shooting Victims