Once-in-a-generation

Geologists describe Sunday's powerful earthquake in the Indian Ocean as a once-in-a-generation event.

Source: tatoeba (12258934)

Zohran Mamdani is a once-in-a-generation political talent.

Source: tatoeba (13571180)

Trump has said that undocumented immigrants share the blame for America’s once-in-a-generation home affordability crisis, but the president-elect’s deportation plans may backfire, driving up the cost of homebuying even further.

Source: wiktionary

Asked if such a service could be put in place again, rather than buses, Mellors said: "I think the key thing is the first two weeks of January are pretty unique, in so far as the renewal of a bridge over the M6 at Penrith is very much a once-in-a-generation project.

Source: wiktionary