Courtney Roberson said the 300-pound gorilla, Little Joe, pushed the door to his exhibition space open and grabbed her, before turning his attention to Nia Scott, the 2-year-old she held in her arms, The Boston Globe reported Wednesday.

"I couldn't believe that I was just attacked by a gorilla at the zoo," Roberson said in Suffolk Superior Court. "I couldn't believe it happened."

Nia Scott's mother, Terrasita Duarte-Scott, is suing the zoo for physical injuries sustained by her daughter during the attack, as well as the persistent psychological damage she claims both mother and daughter suffered as a result of the attack.

"The last time I seen Nia, I saw her in front of the Tropical Forest, being attacked by Joe," Robertson testified. "I remember crying, 'I can't help her!'"

John Linehan, chief executive officer of the zoo, is scheduled to testify Wednesday.

Nia Scott is expected to testify later in the trial.