He didn't actually kill himself. He was stressed out from his Những người bạn not giving him any Lời khuyên to help his pregnant gf get an abortion. He had no choice but to marry her and he didn't really want to and his Những người bạn didn't really treat him well they would use him to take them places also Tony (John) was supossed to call him and that never happened so that's when he goofs off the bridge and he acidently slips off the bridge and gets killed.