Las Vegas law enforcement officials have released a new phone number for people to call and check on loved ones. Call and share this number: 1-800-536-9488.
Facebook also activated its Safety Check feature for Las Vegas, where people were able to let others know they were safe.
Country music star Jason Aldean was performing Sunday night at the end of the three-day Route 91 Harvest Festival when the gunman opened fire across the street from inside the Mandalay Bay Hotel and Casino.
The Associated Press contributed to this report.