A sea lion apparently suffering from disease attacked a swimmer and a beach stroller in San Francisco over the weekend, prompting authorities to issue their first-ever sea lion warning. “We’ve never even heard of something like that, where a sea lion would actually attack somebody swimming,” said Mary Jane Schramm, director of public relations for the Marine Mammal Center. “In the water, the animal typically feels it has nothing to fear from a human.” The swimmer was bitten off Aquatic Park. The sea lion “just swam up to the poor guy and gratuitously bit him on the side of the chest and on the foot,” Schramm said. The animal also attacked a woman who was walking on the beach a few miles away, Schramm said. The woman thought the animal was sick and wanted to help. Neither person was seriously injured. Schramm speculated that the sea lion was suffering from leptospirosis, an often fatal sickness of the liver and kidney.