Las Vegas police say that more than 22,000 people were at the Route 91 Harvest Festival when a gunman opened fire from the upper floors of Mandalay Bay hotel-casino.
Police say that approximately 406 people were transported to area hospitals after the shooting and at least 50 people are dead.
Among those that are dead are an off-duty police officer who was attending the concert. His name is currently being withheld.
PHOTOS: Mass shooting at music festival on Las Vegas Strip
Two other off-duty police officers were also injured. One officer has been upgraded recently from critical to stable condition and the other sustained non-life-threatening wounds.
The shooter has been identified as 64-year-old Stephen Craig Paddock.
The FBI is helping the Las Vegas Metropolitan Police Department. Anyone with information, photos or video from the shooting is asked to call 1-800-225-5324.
