11 people all with different nationalities and different languages get captured and all put in the same room together. one kid holds a tennis ball and is throwing it around while one girl is trying to communicate with the other people and 2 other people crying while the rest choked, suddenly the lights go off and a person is found on the floor,another person checks his pulse and finds nothing, everyone starts to wonder who the killer is.
What happened?

I didn’t come up with it, so sorry if it makes no sense. XD