ITHACA, NY -- The heartbroken parents of the Cornell University student who mysteriously died after attending a fraternity party in October are demanding answers.Freshman Antonio Tsialas attended the off-campus frat party at Phi Kappa Psi in Ithaca, New York, after having dinner with his mother and father, who were in town for parents weekend, WTEN in Albany reported. The 18-year-old soccer team goalie never made it back to his dorm, and his body was later discovered at the bottom of a gorge.His parents, John Tsialas and Flavia Tomasello, said they're offering a $10,000 reward for information."There are people that know what happened, but nothing is being said," John Tsialas said.In a statement, Cornell's president Martha Pollack said officials have not determined Antonio's cause of death but called the party "an unregistered fraternity-sponsored event" where alcohol was served."These events, still under investigation, regrettably follow a pattern of misconduct in the Greek-letter system, a pattern that is emblematic of enduring problems that we, as a community, must recommit ourselves to solving," the statement read The university has since banned fraternity and social events for the rest of the semester.This tragedy comes as fraternities across America are under heightened scrutiny. In the past month, five deaths reportedly involved college fraternities "We have to really take a closer look at these organizations, their practices, the behavior of some of the members," Tomasello said.The Phi Kappa Psi fraternity told ABC News in a statement that they extend their deepest condolences to the Tsialas family and they said their members are working with police in the investigation.University police said they've issued subpoenas and search warrants and will turn over evidence to state investigators.