22 thousand fans are in Las Vegas for a life-affirming celebration of country music. Headliner Jason Aldean launches into his first set. Then the gunfire starts. They are trapped in a killing field. Amid the confusion and chaos, friends and families try to flee but get separated. An off duty firefighter rescues the wounded as instinct takes over. A Black man who felt unwelcome at first risks his life to help. Running left or running right could mean life or death.

Country music artist Dee Jay Silver reunites with his infant son who was in a hotel room with his babysitter on the same floor as the shooter. Flash forward and it's now been five years since that night. Many survivors are still searching for closure. For some, the bond they formed that night with strangers is a silver lining, restoring their faith in humanity. For others, like Ann-Marie and Jim Parsons, who lost their 31 year old daughter Carrie, activism is a way to channel their grief.

A deluge of 911 calls. Are there multiple shooters on the Las Vegas strip? So many wounded, so many killed. Las Vegas Metro PD has officers down. A cop drags his bleeding partner to safety. Between bursts of automatic gunfire, concertgoers make a run for it if they can. SWAT officers converge on the Mandalay Bay Hotel. They now know the shooter is on the 32nd floor. Squinting through rifle scopes, they stage an assault.

At overwhelmed local hospitals, doctors triage the wounded, concentrating resources on treating those most likely to survive. The lobby of the Tropicana Hotel looks like a disaster zone strewn with concertgoers seeking shelter. Country music superstar Jason Aldean, his wife and band members are hunkered down in a tour bus now full of bullet holes. Meanwhile, the SWAT team does not expect what they find. As the nation seeks answers, the FBI joins the investigation.