Local Access Alert
The Local Access Alert (also known as Local Access System or Emergency Override System) is a warning system in the United States designed to warn cable television viewers of impending dangers, such as tornadoes, flash flooding and other civil emergencies. The system was largely replaced by the Emergency Alert System, although it still exists in some areas which have not yet been upgraded, and is still used from time to time in areas that have upgraded to the EAS. Functionality. The Local Access Alert was used by local law enforcement agencies and emergency management staff, and it 's much like the antiquated Emergency Broadcast System. A public servant would dial up a number and PIN through a phone to take control of a certain cable city or cluster in the path of danger. Once the number and PIN are entered, it switches all cable subscribers, regardless of what channel they're on, to a black screen or static and uses a distinct attention signal (in this case, a siren, DTMF tones, steady single (or dual) tones, or multiple hi-lo beeps). Police or emergency management then let viewers know of an impending disaster and instructs them to  take shelter or evacuate. The more modern systems use a black screen with the words "Local Access Alert" in all capital letters, using Trilithic EASyPLUS as the text generator. The problem with the Local Access Alert system is that the operators would have to dial out to end transmission. Simply hanging up the phone connected to such system after an emergency broadcast would not work, and sometimes viewers would hear other phone noises (examples: off-hook and/or a dial tone) before finally being switched back to normal cable operations. One infamous example of this occurred during the 1999 Oklahoma Tornado  Outbreak, when the city of Yukon Police Department, who had broken into the broadcast on Yukon area cable providers with a black screen for a tornado warning, accidentally forgot to dial the necessary code to end the LAA. This cut into important weather information and lost valuable time due to the LAA not having been ended. Viewers reported hearing dial tones a minute after police "hung up," and a phone conversation, likely between the authorities, was mistakenly aired as the ending tones had not been aired. An intercepted message was also aired. Eventually, the alert was ended and normal broadcasting  resumed. With a gradual transition from analog to digital cable, the Local Access Alert has been phased out and replaced by the Emergency Alert System, which employs Specific Area Message Encoding technology to activate for potential disasters and deactivate to resume cable broadcasts, especially late at night when many public servants aren't available to break in.