More than 50 people are dead after a gunman opened fire on a crowd of 22,000 outside the Mandalay Bay Resort in Las Vegas Sunday night.

Nathan Marcus, who owns and operates a food vendor service, was at the concert when the shooting occurred.

Marcus said he didn't pay much attention to the sound and chaos as the shooting began, because he didn't realize what was occurring.

"After there was a break in the shooting and then you could hear like spatters of gunfire, I think that's when everyone realized it was serious and something was going on," Marcus said during a phone interview with WKYC's Andrew Horansky. Listen to their full conversation in the video player above.

Marcus, who owns and operates West Coast Wings out of Orange County, California, said the gunfire seemed to last a steady 10 to 15 minutes.

"A gentleman directly to my right was shot and there was blood sprayed all over me," Marcus recalled. "You can only imagine the scene."

Marcus also said he believes there was more than one shooter.

"To me and all my employees and everyone I spoke with, it seemed there was definitely more than one shooter," he said. "I see that the news and police are reporting there was one, but you could hear fire coming from different directions and different pitches of noise. Some seemed like they were within a hundred feet when they were being fired and some you could tell were from a distance, kind of muffled I would say."

Police entered the Mandalay Bay hotel room of Stephen Paddock, a Mesquite, Nevada native, and found him dead inside. On Monday morning, Clark County Sheriff Joseph Lombardo said it appears Paddock died from a self-inflicted gunshot wound.

Authorities say Paddock, 64, opened fire on the crowd of concertgoers from his 32nd floor room, where police found at least 10 rifles.

Lombardo also said authorities believe Paddock acted alone.

A woman named Marilou Danley, Paddock's roommate, had been named a person of interest. Authorities later said Danley was taken into custody outside the country for questioning and they do not believe she was involved.