Twenty-two thousand fans are in Las Vegas for a celebration of country music. Headliner Jason Aldean launches into his first set - then the gunfire starts.
A deluge of 911 calls causes concern that multiple shooters are on the Las Vegas strip. SWAT officers converge on the Mandalay Bay Hotel, where they now know the shooter is on the 32nd floor.
At overwhelmed local hospitals, doctors concentrate resources on treating the wounded most likely to survive. As officials seek answers, the FBI joins the investigation.
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, activism is a way to channel their grief.
