The New Jersey fireman fatally struck by the mother of the alleged drunken driver accused of killing a South Carolina bride suffered grisly injuries — including the complete separation of his spine from the base of his skull, an autopsy report reveals.

Forest Fire Service Warden Jeffrey Scheuerer, 35, died March 28, 2013, when he was hit by a Jeep Liberty while working a controlled blaze in Clinton Township.

The driver of the Jeep, Traci Komoroski, is the mother of Jamie Lee Komoroski, who is facing multiple charges in the April 28 death of Folly Beach newlywed Samantha Miller.

Scheuerer was standing in a southbound traffic lane at the time of the 2013 collision and flew 45 feet onto the northbound shoulder, according to the autopsy report shared with The Post on Tuesday.

The report revealed that the force of Traci’s vehicle was enough to internally decapitate the two-decade fire veteran.

Scheuerer also suffered a skull fracture and bleeding in the space surrounding the brain, the report said.

In addition to his internal injuries, Scheuerer had abrasions and contusions across his body, including on his head, hips and chest.

While both Scheuerer’s cause and manner of death are redacted in the autopsy documents, initial reports indicated that the crash was a “tragic accident,” and Komoroski was never charged.

But speaking to The Post last week, the victim’s brother, David Scheuerer, said the victim’s family had been frustrated by law-enforcement response to the incident.

“When I went to the Clinton Township Police Department to pick up Jeff’s personal effects, they told me not to worry about Traci, she would be dealt with and proper actions would come from it. … [But there’s been] no actions except silence,” he claimed.

David Scheuerer did not immediately respond to The Post’s request for a comment Tuesday.

Jamie Lee Komoroski, 25, was three times over the legal blood-alcohol limit when she drove her Toyota into a golf cart carrying Miller and her new husband, Aric Hutchinson, from their Folly Beach wedding reception last month, authorities have said. Miller died in her wedding dress.

The suspect, a Coastal Carolina University graduate, remains in custody in Charleston County on multiple charges, including driving under the influence and vehicular homicide.

In a bond motion filed last week, Jamie’s lawyers asked that she be released to a substance abuse treatment program and then into the care of Traci, who lives in Ocean County, NJ.