Multiple witnesses said they heard gunshots just before 8 p.m. while shopping at the location. They said there was chaos after shots were fired. People ran to escape, but the doors were locked, which added to the panic.
"I heard pop, pop, pop, and then look, she almost broke her hand trying to open the emergency doors," said one witness, who added that he was right by the shooting when it occurred inside the store.
Another shopper captured the mayhem that was heard in the aftermath of the shooting.
Footage from AIR7 HD showed the large police presence at the warehouse store after it was evacuated. Following the law enforcement response, Corona police confirmed the shooting incident was stabilized, and there was no threat to the public.
The shooting incident at the Costco in Corona has been stabilized. There is no apparent threat to our community from any outstanding persons. We will release more information as we work to confirm the facts. #coronacostcoshooting— Corona Police Dept. (@CoronaPD) June 15, 2019
Corona police confirmed multiple people were injured inside the Costco. The conditions of those wounded by gunfire were not known.
The person who was shot and killed in the deadly confrontation was a male, but his identity is not known.
Authorities initially thought they were dealing with an active shooter but quickly determined that was not the case.
Investigators said it all began with an argument inside the business, and then moments later, witnesses heard several gunshots.
"There was apparently an argument inside, some type of argument that turned into a gunshot," said Jeff Edwards from Corona PD. "From my understanding, it is not domestic."
Police said the gunman is in custody. He complained of an injury and was taken to a hospital for treatment.
There was also an off-duty police officer involved in the incident, though the nature of his involvement is not clear.
An investigation is ongoing. It is unclear if the store would reopen.