Hawthorne, Nevada (CNN) - People gathered in Hawthorne, Nevada Tuesday to honor seven Marines killed in a training exercise.
Military officials say the Marines were conducting live fire and maneuver training Monday night when a mortar round exploded.
Seven were killed and eight others were wounded.
Officials say the cause of the blast was a 60-millimeter round that detonated inside a mortar tube.
They say the mortar rounds and tubes used to fire them are being pulled from service, pending an investigation.
The military says the exercise was part of regular training required to maintain readiness.