The helicopter was attached to the 3rd Marine Aircraft Wing, according to the spokesman.
Six personnel were onboard the craft when it crashed. They were transported to medical facilities and received treatment after the crash, according to a media statement.
Three people were transported to Scripps Memorial Hospital in La Jolla. Another was taken to Mission Hospital in Mission Viejo.
One Marine was pronounced dead by medical authorities after the crash, according to a Marine announcement Wednesday night.
The cause of the crash was under investigation.
The crash occurred in restricted air space. A small brush fire broke out due to the crash, but it was quickly extinguished by base firefighting personnel.