A Michigan family is grieving as police investigate what caused a dog to attack and kill a 4-year-old boy, reports say.

Shortly before 7 p.m. Tuesday, law enforcement responded to a 911 call from a 14-year-old girl who told officials a dog was attacking her brother Benjamin Cobb while her mother attempted to stop it, according to an article in the Detroit Free Press.

“The mom was in the room at the same time,” Hazel Park Police Chief Brian Buchholz told local reporters. “She heard a low growl, turned and the attack was already happening.”

Michigan Boy, 4, Killed by Pit Bull as Mom Tries to Save Him By Stabbing Dog: 'Worst Nightmare' More

The boy’s mother attempted to stop the attack by stabbing the 60-pound pit bull with scissors and a kitchen knife, according to a report from local news station WXYZ-9, but the boy died from his injuries.

Law enforcement used a taser on the dog and it ran out of the house. Eventually the dog was euthanized, according to the news station.

The family established a GoFundMe account to help with costs of the memorial and other expenses. According to the site, the family released a statement.

“On October 29,2019, we experienced a families worst nightmare when a dog took the life of Benjamin. No words can ever explain the depth of our love for him,” the family stated. “This has taken an unimaginable toll on our family, friends, and all those who knew our sweet boy.”

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According to news radio station WWJ, the family had agreed to take care of the dog for a friend. The dog had been with the family for one day, the station reports.

“I can’t imagine what they’re going through. This is a tragedy and a traumatic, horrific event. It was hard for our firefighters and officers to respond to,” Buchholz told the radio station’s reporter. “Being a part of the family, the mother or a sister to the victim, I can’t imagine what they’re going through.”

On Wednesday, the department released a statement to the newspaper and called the situation “tragic.”

“A preliminary finding appears that this case was a tragic incident,” police stated in an email to the Free Press. “The Hazel Park Police Department extends its sympathy to the family and friends of the deceased.”