[0x62]

The US alone has lost three nuclear weapons which have never been recovered [0].

If you search Broken Arrow you’ll find several lists of past incidents and recovery operations.

[0] https://www.bbc.com/future/article/20220804-the-lost-nuclear...

[MichaelCollins]

Those three are lost and never found. There are more that have been found but not recovered, including two in the USS Scorpion wreck.