Brothers Kulbir Dhaliwal and Paul Dhaliwal claim they are owed unspecified amount of money because the zoo's negligence led to the Christmas Day attack, the San Francisco Chronicle reported.
The two were mauled by a 243-pound Siberian tiger named Tatiana that escaped its enclosure. The tiger killed 19-year-old Paul Dhaliwal's close friend Carlos Sousa Jr., 17, before police shot and killed the big cat.
"Now that we've filed the claims, we'll see whether or not the city is willing to admit that it kept a dangerous animal in a dangerous habitat," said attorney Shepard Kopp, who, with Mark Geragos, is representing the brothers.
City officials have 45 days under state law to offer a settlement or to reject the claim.
"The Dhaliwal brothers' attorneys have made clear from the beginning that they intended to sue the city, and these claims are the procedural first step," said Matt Dorsey, spokesman for City Attorney Dennis Herrera.