An off-duty Fresno County Sheriff's Office K-9 was struck and killed after an illegal firework exploded near him, causing him to run into the street, where he was struck by a vehicle.

The police dog, named Santi, was a 5-year-old Belgian Malinois who had served with the sheriff's office for four years.

"Around 8:30 p.m., the deputy let Santi out into the backyard to urinate. At that time, a mortar shell exploded nearby, frightening Santi, who ran toward the fence, which he completely jumped," the Fresno County Sheriff's Office reported.