A total of 84 A-6's were lost in the Vietnam War. Ten were shot down by surface-to-air missiles (SAMs), two were shot down by MiGs, 16 were lost to operational causes, and 56 were lost to conventional ground fire and AAA.
The last Intruder to be lost during the war was from VA-35 off the USS America, shot down by ground fire on 24 January 1973, while providing close air support.
Twenty U.S. Navy aircraft carriers rotated through the waters of Southeast Asia, from early 1960s & early 1970s. Nine of those carriers lost A-6 Intruders:
USS Kitty Hawk CV-63 lost 14;
USS Constellation CV-64 lost 11;
USS Ranger CV-61 lost 8
USS Enterprise CVN-65 lost 8;
USS Coral Sea CV-43 lost 6;
USS Independence CV-62 lost 4
USS Saratoga CV-60 lost 3;
USS Midway CV-41 lost 2;
USS America CV-66 lost 2
Some of the those Pilots, and their B/N's, also gave the ultimate sacrifice.