CORINNA, Maine — After an adult male pit bull attacked a visiting 7-year-old Bangor boy in early June, the father of the injured child tried unsuccessfully to save his son’s life, according to the medical examiner’s report released Wednesday.

The pit bull, named Koda, attacked Hunter Bragg of Bangor on June 4 while the boy played outside with two other children at the home of Gary Merchant Jr. at 207 Moody’s Mills Road. His father, Jason Bragg, was staying in a camper at the residence and the child was visiting, the report states. Hunter Bragg lived with his grandmother in Bangor, the Corinna animal control officer’s report states.

“The cause of death for Hunter Bragg is: Blunt and sharp force injuries of [his] head and neck,” Mark Belserene, spokesman for the medical examiner’s office, said in a Wednesday email.

Penobscot County Sheriff Troy Morton said Wednesday that the 2½-month-old investigation of the incident is ongoing.

“This thorough investigation remains active, and at this time no other information can be released,” Morton said. “Our office is committed to utilizing all resources necessary to complete this investigation.”

Sgt. Andrew Whitehouse of Penobscot County Sheriff’s Office was the first of many law enforcement officers to arrive at Merchant’s house in response to the attack.

“According to the father, they were all outside when the pit bull attacked, biting [the boy’s] throat and face,” the autopsy report states. “The father carried Hunter inside, called 911 and started CPR. When Sgt. Whitehouse arrived, CPR was still in progress.”

The multicolored, 1½-year-old pit bull that killed Bragg had a history of violence, according to Charles Gould, the local animal control officer. Gould wrote in his report that it did not appear that the animal was provoked.

“Dog [and] child left alone, dog attacked, child died on scene,” the animal control officer’s report states.

The dog formerly lived in Vermont with a relative of Merchant and was registered there until the end of 2015. The dog was brought to Maine in early 2016, after it attacked one of the relative’s other pets, Gould’s report states.

Morton said shortly after the fatal mauling that the dog’s history is a major part of the investigation.

The pit bull was euthanized at Merchant’s request after Bragg’s death, the sheriff said.

The U.S. saw 34 dog bite-related fatalities in 2015, and pit bulls contributed to 28, which is 82 percent of the total, according to The term “pit bull” refers to three breeds: the American pit bull terrier, American Staffordshire terrier and Staffordshire bull terrier.