A little after 10 p.m. on October 1, Stephen Paddock opened fire from the window of his 32nd floor hotel room, shooting at the 22,200 audience members at the Route 91 Harvest Festival concert in the Las Vegas Strip. Paddock killed 59 and injured over 500 in what has become the United States’ deadliest mass shooting.

Officers located Paddock in the Mandalay Bay Resort and Casino, which is hundreds of feet away from where the concert was held, about ten minutes after he started shooting. Paddock shot through his front door at a security guard approaching his room, prompting the officers to wait for backup. When SWAT arrived and entered the room, they found Paddock had committed suicide.

“I went to bed early that night and didn’t hear about it until the morning when I talked to some people who had been out, and it was pure pandemonium,” Greg Carlin, a Parker parent who was nearby in Las Vegas said. “There were rumors that active shooters were around strip properties, and several casinos evacuated and were on lockdown. Police were everywhere.”

ISIS claimed responsibility for the attack, but the FBI does not believe it was involved because Paddock, a  64-year-old retired accountant from Mesquite, Nevada, had no known connection to the group. Authorities are unaware of Paddock’s motive, and the people that were close to him, including his brother and girlfriend, could not think of a reason as to why he committed the atrocity. The Las Vegas Metropolitan Police Department is not considering the event an act of terror.

During history teacher Dan Greenstone’s sophomore “Nations, States, and Terror” class on Monday, students discussed whether or not the attack should be classified as terrorism. “We started the year trying to define terrorism, which surprisingly doesn’t have a consistent definition,” Greenstone said. “This case was interesting because, at this moment, we don’t know what his motivation was, and traditionally most definitions say terrorism has a political purpose.”

On Tuesday, Parker lowered its American and FWP flags in the circle drive to half mast and flew the FWP one upside down as a sign of respect for victims.