first day at case western when the tragedy happened. >> reporter: abraham, lucas, john and michael were all students at case western research university. two were members of a zbt fraternity. according to documents filed in court, his parents believe the students may have been on the plane as part of a zbt fraternity rush or recruitment event. >> we are trying to find out what are the details, who was aware of what was going on? no one from our family knew he was even rushing. >> reporter: the 18-year-old shares some pictures on snapchat just before the crash. about to go on a night flight he wrote on one, rush he wrote on the other.