OCEANSIDE (CNS) - A 6-year-old girl was recovering Wednesday from serious injuries she suffered when a pit bull attacked her at a family friend's Oceanside apartment.

The child and her younger sister were taken to the residence in the 100 block of Canyon Drive on Tuesday by their father, who left them alone inside with the terrier and a German shepherd while he went outside with friends to get groceries from a car, according to Oceanside police Lt. Leonard Mata.

Shortly before 6:30 p.m., the adults returned to find the pit bull mauling the older girl, Mata said. They pulled the dog off of her and called paramedics, who took the victim to Rady Children's Hospital in San Diego for treatment of extensive bite wounds to her face and head.

Humane Society personnel took custody of the terrier, which was expected to be euthanized.

Detectives with the Oceanside Police Department's Family Protection Unit were investigating the attack.

"Depending on the outcome of the investigation, the father could face criminal charges related to leaving the children alone in the apartment with the animals," the lieutenant said.

The owner of the pit bull was not home when the animal went after the child, according to Mata.

The mauling was the second serious dog attack to occur in the San Diego area within two weeks.

On June 14, a pit bull fatally injured an infant in a Lemon Grove apartment, according to sheriff's officials.

The male dog that attacked 8-month-old Tyzhel McWilliams at his mother's West Street residence was put down five days later. Detectives were reviewing evidence in the case to determine whether to recommend any criminal charges over the boy's death, sheriff's Lt. Larry Nesbit said.