What went wrong in Hawaii

The false alarm of a missile heading for Hawaii left Americans wondering how the missile detection and emergency messaging systems are supposed to work -- and what went wrong.

The US military is in charge of detecting ballistic missile launches and maintains a complex and integrated network of sensors and detection capabilities in the Pacific to follow missile activity, a network that has been improved in recent years. Missile launches are detected immediately by satellites that notice the infrared signature on the launchpad. The detection triggers an instant Strategic Command, or STRATCOM, assessment process. The assessment looks at where the launch is, the potent...