Concerts, sporting events, famous landmarks and festivals are just some of the places where people usually feel safe in gathering. That feeling was abruptly shattered in Las Vegas on Sunday night, when 64-year-old Stephen Paddock unleashed a hail of gunfire from the 32^nd-floor of the Mandalay Bay Resort and Casino, taking aim at the 22,000 concert goers attending the Route 91 Harvest Festival.

The Mandalay Bay hotel is a glittering building that offers stunning views of Las Vegas from its upper floors and it overlooked the area where the three-day concert was held. When the gunfire finally stopped, almost 60 people were dead and more than 500 had been wounded

The number of incidents involving active shooters has steadily increased over the last 15 years. In 2000, there was one active shooter incident, and in 2015 there were 20. According to the FBI, the largest number of active shooter incidents occur in a business setting, followed by schools, open spaces and non-military government property.