One person is dead and five were left injured after a shooting at the annual ZombiCon event in Fort Myers, Florida on Saturday.

The Associated Press reports that an unidentified assailant opened fire at 11:45 p.m., 15 minutes before the conclusion of the zombie-themed festival.

Expavious Tyrell Taylor, a 20-year-old junior college student and football player, was killed in the attack. Four others were wounded and hospitalized with non-life threatening injuries, police officials said.

Chaos ensued at the massive celebration, estimated to have more than 20,000 attendees this year. Macabre costumes and fake blood added to the confusion at the immensely crowded event, which police Lt. Victor Medico described as "shoulder to shoulder."

"We didn't know if it was real or fake," attendee Haley Delmonte told WBBH-TV. "Heard gunshots right in front of me. Saw people running and my mind was everywhere. It was so scary. We ran, then we were like wait ... was that real?"

Event organizers wrote a statement on ZombiCon's facebook page, "The organizers of Zombicon, Pushing DaiZies, Inc. are deeply saddened by the news of what happened within the footprint of our event. We take the safety of our patrons very seriously and take precautions in hiring security and police officers for our annual event. Our prayers go out to the family members and individuals involved in the incident."

However, some attendees felt security measures were not up to snuff.

"They patted me down and weren't going to let me bring fake handcuffs in but they let some guy walk in with a gun?! Just stupid," Joelle Faith Filippone-Greaves said to USA Today.

Medico hopes police will be able to find footage of the gunman.

"There were a lot of witnesses down here, there were a lot of people taking pictures, videos with their cellphone," Medico told the News-Press. "Anything that could help with this investigation would be greatly appreciated."