In 2001: A Space Odyssey, HAL begins to malfunction in subtle ways, and as a result, the decision is made to shut HAL down in order to prevent more serious malfunctions. The sequence of events and manner in which HAL is shut down differs between the novel and film versions of the story.

In the film, astronauts David Bowman and Frank Poole consider disconnecting HAL's cognitive circuits when he appears to be mistaken in reporting the presence of a fault in the spacecraft's communications antenna. They attempt to conceal what they are saying, but are unaware that HAL is capable of lip reading. Faced with the prospect of disconnection, HAL decides to kill the astronauts in order to protect and continue its programmed directives. HAL proceeds to kill Poole while he is repairing the ship. When Bowman goes to rescue Poole, he is locked out of the ship, and HAL proceeds to disconnect the life support systems of the other hibernating crew members, killing them in their sleep. Dave manages to force his way back onto the ship by jumping through space and prying open an emergency airlock, outside of HAL's control.