I'm worried about my sisters going to work in city?

A few days ago, my sisters received a call from their friends saying there's a company in capital city is hiring interns and they'll be paid around $3000, they'll get an apartment provided by the company and they'll have to live with complete strangers. They were very excited and quickly made up their minds that they'll be starting working. My mother also agreed. I'm worried seeing them because the capital city is usually dangerous. I had watched a human trafficking drama about girls going to work in city as models but ended being trafficked. It's nerve wrecking. I've talked to them about it but they told me not to worry. It seems like they're too excited about it. I heard they were talking about traveling around the city. They already packed their bags and they'll depart today. What do you think? What should I do? ;(