Kalia, a nine-year-old captive-born female, is pregnant with her first calf and due in December.
As Cetacean News Network pointed out, this incident isn't the first of its kind. In fact, the genetic "grandfather" of Kalia, a wild-caught male named Kotar, reportedly died when he was just 17 years old at SeaWorld San Antonio while he was playing with a gate in 1995. The gate closed on his head, causing a fracture and severe blood loss.
In response to the video of Kalia stuck in the gate, SeaWorld argued:
The gates at Shamu Stadium use a small amount of pressure, and open and close slowly. The whales can easily move them when the trainers begin a gate cycle. Gate play is an enjoyable game for the whales. When a whale is playing with a gate, the trainers are always nearby. Check out some of the killer whale trainers discussing gate play.