NORFOLK, Va. (AP) — Norfolk Naval Station is holding a memorial service for two sailors who were killed in a helicopter crash in the Gulf nation of Oman.

The Navy says the Norfolk-based MH-53 Sea Dragon crashed 58 miles southwest of the Omani capital Muscat on July 19. Forty-year-old Senior Chief Aviation Warfare Systems Operator Sean P. Sullivan of St. Louis and Naval Aircrewman 2nd Class Joseph P. Fitzmorris of West Monroe, La., were killed. Three other crew members survived the crash.

Media outlets report that the memorial service for Sullivan and Fitzmorris will be held at 11 a.m. Thursday at the Norfolk Naval Station chapel.

The cause of the crash remains under investigation.