Family mourns son's death in Marine copter crash that claimed seven lives Outside the Everett family home stands a large photo of their son Justin, a Marine who died in a training exercise when two helicopters collided around the California-Arizona border in one of the Corps' deadliest aviation training accidents in years. Sgt. Justin Everett, 33, a helicopter pilot and Marine for a decade, had served two tours in Iraq and was slated to head to Afghanistan in July, his father, James, told The Fresno Bee. A father of a 5-year-old daughter and a 2-year-old son, two of his brothers served in the Air Force. Everett was one of seven Marines who died when their AH-1W "Cobra" and UH-1Y "Huey" helicopters collided in midair Wednesday night. They had been conducting a routine training exercise at about 8 p.m. local time when the incident occurred, Marine officials said. Six of the Marines had been stationed at Camp Pendleton in California and one in Yuma, Ariz. The cause of the crash, which occurred about two miles west of the Yuma Training Range Complex on federal land, continued to be under investigation Friday. The identities of the Marines killed have not been released pending formal notification of next of kin. "It's an unfortunate consequence of the high tempo of operations," retired Marine Col. J.F. Joseph, an aviation safety consultant, told The Associated Press. They're out there working on the edge trying to exploit the maximum capabilities of the aircraft and their tactics. Just by the virtue of that, in becoming combat ready, these unfortunately are not uncommon occurrences. The AH-1W, which carries a pilot and gunner, and is considered the Marine Corps' main attack helicopter. The UH-1Y can hold one or two pilots, a crew chief and other crew members, the AP reported. Hueys often are used to pick up and drop off ground crews, while Cobras hover by ready to fire if the Huey comes under attack. Training accidents It was the fifth aviation accident since March involving the 3rd Marine Aircraft Wing headquartered at Miramar Marine Corps Air Station in San Diego. In the Navy and Marine Corps, there have only been two other aviation training accidents in the past five years involving seven or more deaths, according to the military's Naval Safety Center, the AP reported. Last September, two Marines died when their AH-1W Super Cobra helicopter went down in Camp Pendleton, according to the Marine Corps Times. And in July, a Marine sergeant was killed in the crash of a UH-1Y Huey helicopter, also at Camp Pendleton, while five others onboard were injured, the Marine Corps Times reported. In one of the worst accidents in the last five years, an AH-1W collided with a Coast Guard C-130 airplane in October 2009, killing two aboard the Marine helicopter and seven aboard the C-130, The AP reported. "We fly every single day for the most part and, you know, relatively mishap free so it's ... one of those rare and unfortunate occurrences that took place last night (Wednesday)," Cpl. Steven Posey of the 3rd Marine Aircraft Wing in Miramar in Southern California told msnbc.com. Chaplains gathered after the collision to inform relatives of the victims. "This is a dynamic, very tight-knit wing," U.S. Navy Capt. Irving Elson, the Aircraft Wing's senior chaplain, told The Orange County Register. The tragedy didn't just happen to the squadron, it happened to the Marine Corps, it happened to the nation and it happened to us.