The claim states the city and county of San Francisco own the property where the zoo is located and have a responsibility to the public to prevent injury by animals at the zoo.
The claim also says the two brothers, Kulbir and Amritpal (commonly known as Paul) Dhaliwal, have been defamed by a PR firm working for San Francisco and the zoo.
The pair were injured on Christmas Day after a 250-pound Siberian tiger scaled the walls of its enclosure, attacked them and killed their friend, 17-year-old Carlos Sousa Jr. The animal eventually was shot dead by police.
The walls of the outdoor enclosure later were found to be lower than the height recommended by an accrediting agency for the nation's zoos.