‘Mom, are we going to die today? Why won’t you answer me?’ – False Nuclear Alarm in Hawaii Due to User Interface


Image from the New York Times

The morning of January 13th, people in Hawaii received a false alarm that the island was under nuclear attack. One of the messages people received was via cell phones and it said:“BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL.” Today, the Washington Post reported that the alarm was due to an employee pushing the “wrong button” when trying to test the nuclear alarm system.

The quote in the title of this post is from another Washington Post article where people experiencing the alarm were interviewed.

To sum up the issue, the alarm is triggered by choosing an option in a drop down menu, which had options for “Test missile alert” and “Missile alert.” The employee chose the wrong dropdown and, once chosen, the system had no way to reverse the alarm.

A nuclear alarm system should be subjected to particularly high usability requirements, but this system didn’t even conform to Nielson’s 10 heuristics. It violates:

  • User control and freedom: Users often choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.
  • Visibility of system status: The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.
  • Error prevention: Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
  • Help users recognize, diagnose, and recover from errors: Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.
  • And those are just the ones I could identify from reading the Washington Post article! Perhaps a human factors analysis will become regulated for these systems as it has been for the FDA and medical devices.