This is the 454th most frequent Russian word.
пассажиров
"Passengers."
The word 'пассажиров' here is in the accusative plural case, indicating the direct object, referring to passengers being acted upon (let out).
Автобус прибыл, и пассажиров выпустили.
The bus arrived, and the passengers were let out.
Here, 'пассажиров' is in the genitive plural case, as it denotes 'of passengers' in the context of assistance with their transfers.
Я помог организовать пересадки пассажиров на другой поезд.
I helped to organize the transfers of passengers to another train.
'Пассажиров' in this context is in the genitive plural case, used to indicate possession or quantity, specifying the attribute 'many passengers'.