What happened with Sisi and Rosu?

Guys, if you have not watched it yet, do not read the content below (It may contain spoilers).



I was wondering what could have happened with those two boys. After Sisi e Rosu went to that building to collect water Sisi stays behind and he does not appear in any scene after this.

And Rosu, after stealing the car with Pasa, he disappears and there are no mentions about him after this, even though Pasa comes back and it's possible to see how injuried Pasa is and how damaged the car is.

What could have happened with these two boys? Any ideas?