Hmm,
A "Broken Arrow" is the term used.
I'm pretty sure the Canada incident Nuke was recovered.
But, the So Carloina/Georgia? incident Nuke has not been found.
B-47 crew, major in flight emergencey (IFE) and the Dash 1 (Flight Check-list manual) mandated to "drop weight" which meant the "package"
Being a 8,000 Lb MK15 weapon, the casing is Non-ferrous (Alloy) and has been undetectable to magnometers/Ground Penetrating RADAR and other types of detecting equip.
"We" have had numerous other "Broken Arrows"
Chronological order:
1. May 22, 1957: Kirtland Air Force Base, New Mexico
2. February 5, 1958: Savannah River, Georgia
3. March 11, 1958: Florence, South Carolina
4. November 4, 1958: Dyess Air Force Base, Texas
5. January 24, 1961: Goldsboro, North Carolina
6. March 14, 1961: Yuba City, California
7. January 17, 1966: Palomares, Spain (One of my Air Force "Buds" was an Airman at the timewas tasked (with others) to walk in a "grid-pattern" for acres & acres in Spain picking up debris. Later in life he had 27 tumors removed from his body...He is living in Nevada today)
8. January 21, 1968: Thule Air Force Base, Greenland (I think the Thule Greenland one fell thru the ice, it was a B-52 crash incident)