According to the command investigation, no one was at fault for the death of Lieutenant James A. Mazzuchelli. He was killed when the tail rotor blade of UH-1Y Venom hit his head and cut through his helmet and night vision device.

According to the investigation, when Mazucelli "inadvertently stepped into the rotating rotor" in February 2018, the blade made a nearly one-foot-long wound on his head, causing "irreversible brain damage."

However, an investigation obtained by the Marine Corps Times through a government record request revealed that the route to Camp Pendleton, California had some omissions in medical emergency response procedures.

Nearly 15 minutes after Mazucelli was hit by the rotor blade, fire and emergency medical personnel from Camp Pendleton, California arrived at the scene-an investigator pointed out that the time to call emergency services appeared to be "too long."

The confusion about who to call and how to provide emergency services for the airline seems to have played a role in delaying Mazuccili's arrival at the higher level of medical care at Scripps Memorial Hospital in La Jolla, California.

"Although military aviation operations are inherently dangerous, the loss of any service member will weigh the hearts of the 3rd MAW [3rd Marine Corps Aircraft Wing] family," a 3rd MAW spokesperson told the Marine Corps Times.

The spokesperson said: "The third MAW will continue to improve our safety procedures to reduce the risk of fatal accidents in the future."

At around 6:07 pm on February 21, 2018, flying surgeon Mazuccili, assigned to Navy Light Attack Helicopter Squadron 267, was hit by the tail rotor blade.

Investigations revealed that Pendleton Provost’s office did not get through until 6:14 in the afternoon, and 911 did not get through until 6:16 in the afternoon.

On the night of the accident, Mazucelli and the other four crew members of UH-1Y Venom were reading the training exercise.

The maintenance and crew of the HMLA 267 seemed to be confused about who controlled the gate of the flight path and the scene of the Mazuccili accident. The phone call to the office of the dean of the airport showed that the office could not open the door. A Marine who could enter the gate was quickly identified and posted.

However, the base’s fire department and emergency services department was delayed for several minutes due to inaccurate directions, as well as confusion about the building numbers near the accident site and the correct door to the flight route.

The investigation pointed out that the emergency team closest to the accident was the aircraft and fire brigade of the airport, but they never received a call.

Navy Lieutenant James A. Mazzuchelli died after being hit by the tail rotor of a UH-1Y Venom helicopter on February 21, 2018. (Marines)

"All units need to know the quickest way to call emergency services," Colonel Matthew Murray, the former commander of the 39th Marine Corps, wrote during the investigation.

In addition, when Mazuccili was hit, there was some confusion as to how to treat and first aid the head wound of the lieutenant. The investigation revealed that a sergeant expressed “a little hesitation about applying gauze on exposed brain material”.

A Marine Corps lieutenant and sergeant bandaged the back of Mazucelli's skull to stop the bleeding.

Sometimes when Mazucelli was receiving treatment, a corporal pointed out that he had signs of breathing and was "somewhat reactive."

At 6:27 pm, Mazucelli was placed in the back of the ambulance. Two minutes later, first responders were told to join Pendleton’s air ambulance at the base naval hospital.

By 6:55 in the afternoon, Mazucelli was on his way to Scripps Hospital, where he underwent a craniotomy-a surgical operation that exposes the brain.

According to the details of the investigation, Mazucelli had a laceration of 27 cm on his head and suffered "extensive brain injury". He was admitted to the intensive care unit and was pronounced dead on February 24, 2018 nearly three days later.

Although there were some mistakes that prevented emergency services from reaching the scene, the investigation showed that there was "almost no way" to save the life of a navy lieutenant.

After the accident, Mowery instructed his safety department to formulate a reference guide to outline emergency procedures, coordinate the firefighting and aircraft rescue at the airport, and briefly introduce emergency services to the staff on duty and supervisors.

The investigation described the accident as an "unfortunate accident" and did not mention misconduct among the personnel.

Investigations revealed that when Mazucelli bypassed the rear of the aircraft and "passed the arc of the tail rotor," he was hit by a blade when the No. 1 engine started.

However, the crew member who spoke with the investigator did say that walking behind the tail rotor is not a “normal procedure” and the crew has received training not to do so.

The accident caused minor damage to the aircraft. Two of the four tail rotor blades have markings from Mazucelli's helmet and night vision goggles.

DaCid Cheers, Mazzuchelli's stepfather, told Action Jax News that his stepson died doing what he liked to do.

"We express our deepest sympathy to the Mazucelli family and the people affected by this tragedy," said a third MAW spokesperson.

Sean Snow is a senior reporter for the Marine Corps Times and a Marine Corps veteran.