20 years after deadly quake, Istanbul not ready for 'Big One'

ISTANBUL - Twenty years after a devastating earthquake ravaged the northwest of Turkey, Istanbul people live with the knowledge that another "Big One" is unavoidable, and that their city of 16 million is not prepared.

On Saturday, Turkey will mark the anniversary of the magnitude-7.4 quake that hit Izmit - around 100 kilometers east of Istanbul - on Aug 17, 1999, killing at least 17,400 people, including 1,000 within the economic capital of the country.

The question for seismologists is not if another earthquake will hit Istanbul, which lies along the volatile North Anatolian tectonic plate. The only question is: When?