But if not for recent active shooter training, the outcome could have been far worse, police said.
Customer Carlos Odom was walking out of the store when “I heard a bunch of gunshots. Pop pop pop pop — more than a dozen shots,” he said.
“I just thought ‘run!’ and ran to my car. This is crazy. The world is crazy nowadays.”
The suspect has been identified as a disgruntled employee who had a personal grievance with a manager, Southaven Mayor Darren Musselwhite said, but their name was not released.
Both the suspect and a responding officer were shot and treated at local hospitals, authorities said.
The officer “was saved by his [bullet-resistant] vest,” Southaven Police Chief Macon Moore said.
The condition of the suspect at the Regional One trauma center has not been released.
Walmart issued a statement offering condolences to the victims and their families.
The city is mourning the deaths, but some say recent police training helped prevent the loss of more lives.
Two weeks ago, Southaven police and firefighters underwent active shooter training at a nearby school, Moore said.
The police chief said there’s “no doubt that that training saved lives today.”
CNN’s Gianluca Mezzofiore and Dylan Miettinen contributed to this report.