Moody Gardens Aquarium lost a couple of sharks due to a spike in ozone over the last day or two.
Moody, like commercial aquariums everywhere, has a top-o-the-line filtration system, heavily regulated, very smart and modern. But it glitched.
When the workers arrived in the morning two sharks were bottom dead, and two were "distressed". So they sent divers into the water (dropping jaw) to give the sharks shots....
Personally, I'd think that any shark (they are never tame) that would allow a diver to give it a shot is likely dead already.