(**New alert) Local native among those killed in mortar explosion in Nevada during Marine training exercise...

A Jamestown native is among those who were killed earlier this week in a Marine night training exercise in Nevada.  The uncle of Lance Corporal Mason Vanderwark says his nephew was among the seven Marines killed when a mortar shell exploded late Monday night.  Mason... who was 21... and the others were members of the 2nd Marine Expeditionary Force.  His uncle -- Dwayne -- is in Hickory, North Carolina with Mason's widow, and his mother, Melissa.  Dwayne Vanderwark says the tragic part is that Mason had been doing this kind of work during two previous tours of duty overseas... including Iraq.  He says Mason  was on the "front lines" and didn't get a scratch.  Dwayne Vanderwark -- whose from Lakewood -- says it's been a difficult time for Mason's 19 year-old wife, Taylor, and his sister.  However... he says the support they're received from family, friends, and fellow Marines has been "overwhelming..." and, it helps.  Mason Vanderwark was born and raised in Jamestown... and, is the only son of Melissa Vanderwark.  His uncle says an autopsy is being performed on all seven Marines... and, the bodies should be released to the families late next week.  With that... funeral arrangments are incomplete.