March 31 (UPI) -- Two Marine Corps pilots were killed in a helicopter crash in Arizona, the Marine Corps Air Station Yuma said Sunday.
Officials said the incident occurred at about 8:45 p.m. on Saturday, as the two pilots were conducting a routine training mission as part of the Weapons and Tactics Instructor course in a AH-1Z Viper helicopter.
The names of the pilots weren't immediately released and the station said further updates would be provided at a later time.
An investigation into the cause of the crash is ongoing.
