There was an event nearby, so work was really busy since there were a lot of people
例えば、
A: How was your weekend?
週末はどうだった？
B: There was an event nearby, so work was really busy since there were a lot of people
(バイト先に)近くでイベントがあったから、人が多くて忙しかった
個人の好みですが、私だったら、
There were a lot of people around where I work because there was an event nearby, so work was really busy.
直訳：近くでイベントがあったからバイト先の周りに人が多くて、バイトが忙しかった
と言います。
ご参考になれば幸いです。
There was some kind of event happening near my work place, so we were quite busy.
この場合、次のような言い方ができますよ。
A: How was your weekend?
「週末どうだった？」
B: I was working at my part-time job, and there was some kind of event happening near my work place, so we were quite busy.
「アルバイトだったんだけど、職場の近くでなにかイベントをやっていたから、すごく忙しかった」
ご参考まで！
アメリカ合衆国 
カナダ 
