The three adorable mountain lion cubs named Fern, Thistle and Spruce were believed to have been orphaned after their mother was killed by a car.

Authorities believe their mother was hit and killed by a vehicle in the Portola Valley area of San Mateo County in the San Francisco Bay Area, zoo officials said. The mountain lion carcass has since vanished, so they can’t confirm her relationship to the cubs through DNA.

Three orphaned mountain lion cubs were brought to the Oakland Zoo for rehabilitation and care after their mother was believed to have been fatally struck by a car.