NEWBURGH, N.Y. — Hundreds have gathered to remember nine Marine Corps aviators who were killed when their New York-based transport plane crashed in Mississippi last month.

A memorial service Sunday was held inside a hangar at Stewart Air National Guard base in Newburgh in New York’s Hudson Valley, where the nine were based. They were in a Marine Forces Reserve transport squadron.

A total of 15 Marines and a sailor died when their C-130 transport plane crashed in soybean fields in the Mississippi Delta on July 10. The other seven servicemen killed in the crash included six Marines and a Navy corpsman from an elite Marine Raider battalion at Camp Lejeune, North Carolina.

The plane was headed for training in Arizona. The cause of the crash remains under investigation.