Harsha Maddula disappeared just after midnight Saturday morning. Friends saw him leaving an off-campus party. Later, they realized he wasn't with them as they walked to another party.
Maddula's parents flew in from Long Island, New York, on Monday. His mother says Harsha is diabetic.
Northwestern University police have sent an e-mail to students and staff to contact them if they have any information. They are also studying tapes and other electronic records from campus.