Child was victim of abuse attempt

This evening while at an event our 6 year old child was left only briefly with another older child (~12). Shortly after I left she came looking for me desperately and was clearly distraught. Initially she didn't want to tell me why but then eventually told me that the older boy had tried to touch her belly and her lifted her dress to touch her underwear. She ran away and came to find me. We don't know the boy, he was a mutual friend. The event we were at was funeral for a close friend. Not sure what to do, if anything. via /r/Parenting http://ift.tt/2tLJTJl