Short answers, pulled from the story.
James Dallas Egbert III entered the steam tunnels beneath Michigan State University on the 15th of August 1979. He never emerged from the tunnels and left behind a suicide note.
Dungeons and Dragons became the central focus of the investigation after police and media linked the game to Egbert's disappearance. This connection transformed a local missing person case into a national sensation and increased sales of game manuals from 5,000 copies to over 30,000 copies by the end of 1979.
James Dallas Egbert III survived the night in the tunnels and went into hiding at a friend's house before moving to New Orleans. He found employment as a laborer at an oil field in Morgan City, Louisiana, where he remained for four days before contacting private investigator William Dear.
William Dear was a private investigator hired by Egbert's parents on the 22nd of August 1979 to find the missing student. He resolved the case when Egbert called him from Louisiana, and both parties agreed to keep the details of Egbert's whereabouts secret.
James Dallas Egbert III died on the 16th of August 1980 at the age of 17 after being admitted to Grandview Hospital in Dayton with a self-inflicted gunshot wound. He had been admitted on the 11th of August 1980 and his organs were distributed to patients in several states including New Jersey.
William Dear authored the book The Dungeon Master: The Disappearance of James Dallas Egbert III in 1984 to document the case. The story also inspired the novel and film Mazes and Monsters, which heightened public unease regarding role-playing games during the 1980s.