This sentence doesn't work in English. It should be "the First City"
That's also accepted as a translation, but the main translation treats "First City" as a name, like (say) Mexico City, where we wouldn't say "I live in the Mexico City" but instead simply "I live in Mexico City".
Doesn't simple past work here? I mean, occurred instead of has occurred.
We generally expect an answer in a perfect tense (has occurred, had occurred, will have occurred) in English where the Klingon has -pu'.