WASHINGTON — The Marine Corps has grounded its fleet of KC-130Ts “out of an abundance of caution” following the events of the deadly crash earlier this month, the service has confirmed to Defense News.

The grounding affects 12 aircraft total, all operated by Marine Forces Reserve, said spokeswoman Lt. Stephanie Leguizamon.

“Out of an abundance of caution, the Marine Corps took the prudent action not to fly our KC-130T aircraft in the wake of the mishap on July 10 until further notice,” she said.

Marine Corps KC-130Js, as well as Navy and Air Force C-130 variants are not affected by the temporary halt in flight operations. All C-130 variants are manufactured by Lockheed Martin.

On July 10, a KC-130T crashed in Mississippi, killing 15 Marines and one sailor. It was the deadliest crash for Marine aviation since 2005. The plane came from Marine Aerial Refueler Transport Squadron 452 in New York, which flies KC-130s that are modified to provide aerial refueling capabilities.

Leguizamon declined to say when the Marine Corps had made the decision to ground its KC-130T fleet or whether it was due to initial findings from the investigation, which is still ongoing.

Preliminary indications are that “something went wrong at cruise altitude,” Brig. Gen. Bradley S. James, commanding general of 4th Marine Aircraft Wing, told reporters on July 12. “There is a large debris pattern” and two major impact areas a mile apart, he added.

The plane was carrying ammunition for personal weapons, prompting an Explosive Ordnance Disposal Team to comb the wreckage for unexploded ordnance. Officials have not said if the ammunition might have blown up in flight, but witnesses reported hearing a loud noise before the plane crashed.

“It sounded like a big thunderstorm,” local catfish farmer Will Nobile told the Associated Press. “Not one big explosion, but a couple of second-long explosions. … A long, steady rumble is what it was.”

Jeff Schogol of Marine Corps Times and David Larter contributed to this report.