Sig Alert

Sig alert, Sig-alert or Sigalert in California, as well as other parts of the United States, means an incident that significantly disrupts road traffic.

A Sigalert is defined by the California Highway Patrol (CHP) as "any unplanned event that causes the closing of one lane of traffic for 30 minutes or more".

By the early 1950s, the rapidly growing number of automobiles in Los Angeles had greatly increased the frequency and severity of traffic accidents and jams.

Sigmon had worked for Golden West's station KMPC 710 in 1941 but found himself in the United States Army Signal Corps during World War II, assigned to General Dwight D. Eisenhower's staff, in charge of non-combat radio communications in the European theater.

The alert described the derailment of a passenger train near Los Angeles' Union Station and requested any available doctors and nurses to respond to the scene.

[8] At first, the LAPD issued about one alert a day, but soon other agencies were calling in messages they wanted broadcast, including rabid dog reports, gas leaks and even a ship collision in Los Angeles Harbor.

[9] A pharmacist who had made a potentially fatal error in filling a prescription took advantage of the system to warn the customer (who heard the SigAlert in time).