P-22, the celebrated mountain lion that took up residence in the middle of Los Angeles and became a symbol of urban pressures on wildlife, was euthanized after dangerous changes in his behavior led to examinations that revealed worsening health and injuries likely caused by a car. Officials with the California Department of Fish and Wildlife on Saturday said the decision to euthanize the beloved big cat was made after veterinarians determined it had a skull fracture and chronic illnesses including a skin infection and diseases of the kidneys and liver. “His prognosis was deemed poor,” said the agency’s director, Chuck Bonham, who fought back tears during a news conference announcing the cougar’s death. “This really hurts … it’s been an incredibly difficult several days.” The animal became the face of the campaign to build a wildlife crossing over a Los Angeles-area freeway to give big cats, coyotes, deer and other wildlife a safe path to the nearby Santa Monica Mountains, where they have room to roam. Seth Riley, wildlife branch chief with the National Park Service, called P-22 “an ambassador for his species,” with the wildlife bridge a symbol of his lasting legacy. State and federal wildlife officials announced earlier this month that they were concerned that P-22 “may be exhibiting signs of distress” due in part to aging, noting the animal needed to be studied to determine what steps to take.