Four U.S. Marines were killed Wednesday in an accident at Camp Pendleton in Southern California.
The incident occurred about 11 a.m. during a range maintenance operation at the San Diego County base, authorities said in a statement. According to reports, an unexploded ordnance may have detonated during the cleaning of an artillery range.
"We offer our heartfelt prayers and condolences to the families of the Marines lost today in this tragic accident," Brig. Gen. John W. Bullard said. "Our first priority is to provide the families with the support they need during this difficult time."
Officials said the identities of the deceased Marines will be released within 24 hours of the notification of their families.
The exact cause of the accident is currently under investigation and more information will be provided as it becomes available.