Officials at SeaWorld San Antonio confirmed that "Bella" the beluga whale died Sunday.
"We are saddened to report that a beluga whale died today (Sunday) after a brief illness," read a brief statement from a park official. "The 4-year-old female beluga was born at SeaWorld San Antonio."
Beluga whales are very sociable animals and are able to interact with people.
SeaWorld operates a Beluga Interaction Program that allows park guests as young as 7-years-old to go into the water with the belugas.
As of Sunday there was no word on what specific illness the whale was battling.
Park officials are now investigating the death.
"A necropsy is being performed, though results are not expected for several weeks," the statement read.