The boy was identified as 2-year-old Lucas Anthony Tang.
Tang was with his parents all night when he fell from the third deck of luxury seats to the arena's lower bowl several minutes after the Los Angeles Lakers beat the Golden State Warriors 117-89.
The boy had somehow made his way to the end of the luxury suite, went past the partition and fell to the concrete floor at about 9:15 p.m.
The parents told investigators that Lucas had been scooting around the luxury suite when they became distracted taking pictures. Then they realized he had fallen over the side.
Witnesses said the boy was seen moving his arms and legs while being put on a stretcher. He was rushed to L.A. County-USC Medical Center, where he later died.
In response to the tragedy, the Staples Center and AEG released a statement: "Our condolences and prayers go to the Tang family. We are working with Los Angeles Police Department on the investigation of this tragedy."
In the 11-year history of the Staples Center, there has never been an accident like this one.
The LAPD Juvenile Division is investigating the case as a matter of routine procedure in a child's death to see if negligence was involved.