(Seattle, WA)  --  The National Oceanic and Atmospheric Administration is confirming the death of southern resident orca J50.  NOAA spokesperson Michael Milstein tells KING 5 the young orca is "certainly dead by now" after falling off researchers' radar nearly two weeks ago.  Milstein says J50 was suffering from a condition called "peanut head," which is fatal for the majority of whales.  The Center for Whale Research declared J50 presumed dead last week, but NOAA continued to search for her until late last week.  J50's death brings the critically endangered southern resident orca population down to 74.