[alternatives?]

That still leaves them 175 to explain why they hired.

[In_Iowa_not_from]

That still leaves them 175 to explain why they hired.

I would guess other Asians (Filipinos, Malaysians, Vietnamese) who had worked at their other construction sites in Asia. I would guess that these foreigners were temporary construction workers who were working on the expansion. That's why they snuck in on a tourist visa-- they're here only to do a construction job then planned to go back to Asia to work on the next Korean contruction job.