A college student was killed and four others were critically injured in a road accident on GST Road near Guduvanchery on Saturday night. A senior official of Guduvanchery police said Karthik, Surya Senathipathy and Venkat were riding on a two-wheeler on GST Road when another two-wheeler, on which two other students — Sivaji and Suman — were travelling, hit theirs. Surya Senathipathy, a student of a private college near Kattankulathur, was killed on the spot, while the four others suffered serious injuries.