St. Helena Island, South Carolina - South Carolina is reeling after a mass shooting at a bar on St. Helena Island claimed multiple lives on Sunday.

The shooting reportedly occurred during a Battery Creek High School alumni celebration at Willie's Bar & Grill around 1 AM on October 12.

"Upon arriving at the scene deputies made contact with a large crowd of people, several of which were suffering from gunshot wounds. It was learned that hundreds of people were at the location when the shooting occurred," the Beaufort County Sheriff's Office said in a statement.

"At this time, we know that at least 20 people were injured. 4 were transported to area hospitals in critical conditions and 4 victims were pronounced deceased at the scene," the sheriff's department said.

"It was just mayhem, a tragedy, outside," the bar's owner, Willie Turral, told WJCL. "It’s just unreal."

Turral said that a security guard was among those killed.

Investigations into the shooting are underway. Anyone with information on the incident has been urged to contact the Beaufort County Sheriff’s Office.

St. Helena is known as a cultural center for Gullah Geechee people, descendants of formerly enslaved Africans who have nurtured their own creole language and customs with direct ties to Central and West African cultures. Willie's Bar & Grill serves Gullah cuisine.