According to reports by FOX affiliate WBRC-TV in Birmingham, the shooting happened at the Riverchase Galleria shopping mall.
"We already had multiple officers working at the mall for traffic control and police presence inside". A 12-year-old girl also was hit by gunfire, but she was alert, talking and taken to a nearby children's hospital.
He said that the 18-year-old has at least one gunshot wound and "We believe he is in serious condition". Now, mall officials said the mall will remain closed until further notice.
Another witness speaking to Al.com heard numerous shots before people started leaving the mall via an entrance close to a Journey's store.
Derzis said he doesn't understand it, but "for some reason, people think when they get engaged in some sort of altercation that it's OK to pull out a gun and shoot somebody, and it's not".
More than 200 still missing in California's deadliest wildfire on record
Also known as the Camp Fire , it has ravaged more than 111,000 acres of land and burned more than 6,000 homes. By early afternoon, one of the two black hearses stationed in Paradise had picked up another set of remains.
He added: "We know the deceased was armed with a handgun and we know he shot the person who was transported (to the hospital)".
Brookfield Properties, which owns the shopping center, said it was devastated by the shooting.
The city followed up with a tweet at 12:09 a.m.to thank the police officers and paramedics who responded to the scene, saying, "Our HPD officers acted heroically and professionally tonight".
Two officers who were providing security at the mall heard the gunfire and approached the area.
The Jefferson County Sheriff's Office will lead the investigation into the officer-involved shooting.
"You just don't bring guns into a crowded mall", he said.