Saved by the Bell is an American television sitcom that aired on NBC from 1989 to 1993. The series was a retool of the Disney Channel series Good Morning, Miss Bliss. The show follows the exploits of a group of friends and their principal, and although the series primarily showcases light-hearted comedic situations, it occasionally touches on serious social issues, such as drug use, driving under the influence, homelessness, divorce, death, and environmental issues. This made Saved by the Bell a precursor to later shows (such as Beverly Hills, 90210, Dawson's Creek, and The O.C.) that introduce young audiences to critical moral dilemmas.