Three of the five sea lions at the Aquarium of the Pacific -- two females and a pup -- have died, officials said Saturday.
The death of 7-year-old Roxy and the demise of 4-year-old Kona and her baby were unrelated, a spokeswoman for the Long Beach facility said, but occurred within a 24-hour period.
Roxy had a lethal reaction to anesthesia about 5 p.m. Friday during emergency surgery. The pinniped, who came to the aquarium as a pup after being abandoned during an El Nino storm, needed medical attention after suffering complications while giving birth to a stillborn pup the previous night.
Aquarium staff don't know what caused the deaths of Kona and her 4-week-old pup. After Kona gave birth on Memorial Day weekend, the pair spent two weeks in a special area next to the sea lion exhibit before being moved to a behind-the-scenes nursery.
They appeared healthy and active about 1 p.m. Saturday, but an hour later a staff member found both sea lions motionless. Efforts to revive the animals failed.
Staff members were particularly saddened to lose the pup, the first to be born at the aquarium since it opened eight years ago.
"We haven't even had a pregnancy, so this was really a big deal to all of us," said Cecile Fisher, aquarium spokeswoman.
The staff had just come to terms with Roxy's passing when they learned Saturday about Kona and her pup.
"It's like having three of your pets in your house dying all at the same time," Fisher said. "We all love our animals, and for anything to happen to one of them is bad, but for this to happen to three is just terrible."
Aquarium officials expect necropsy results today.