Two adults with gun shot wounds were taken to the hospital in unknown condition. An off-duty officer from another agency was among the injured. The names of the adults injured have not been released.
Police said they detained the suspect and took him to the hospital after he told them he was also injured.
The man who died was not immediately identified.
Lt. Jeff Edwards said the gunman was arguing with another man when he when he pulled out his gun and fatally shot the man.
Witnesses also told CBS Los Angeles they heard an argument before seven or eight shots rang out in the store.
Corona Police tweeted at 12:09 a.m. Saturday that the shooting incident “has been stabilized,” and there was “no apparent threat,” to the community.
The shooting occurred in the crowded shopping center with shoppers leaving personal belongings behind as they fled.
Corona police have secured those items and will release them to owners with proper identification.