(Diamond Lake, OR)  --  Authorities are investigating after the body of a volunteer firefighter was found in Diamond Lake.  The Douglas County Sheriff's Office says 51-year-old Rodney Shay was presumed drowned after he jumped into Diamond Lake on July 25th and didn't resurface.  His body was found around 3:10 p.m. yesterday.  Shay was a member of the Pleasant Hill Volunteer Firefighters Association.