Four Marines were handling unexploded ordnance on a firing range, according to base officials. The incident occurred at approximately 11 a.m.
The Marines were killed during a range maintenance operation. It was not a live fire exercise. Maintenance teams are sent to recover or neutralize unexploded ordnance after a live fire exercise in which some shells do not go off.
No one else was injured, according to the base.
The deceased Marines were not immediately identified pending notification of next of kin.
The incident was under investigation.