Car Starting Issue on 2005 Kia Amanti

On Oct 5, 2010, I started my car as normal going to the gas station. Turn off vehicle and was there for about 20 minutes talking with someone. When leaving, I turn the car on. Lights came on and radio. When putting it in ignition the car shut off completely. No lights or power through the whole vehicle. I waited for 15 min. and the car started up again. What could've have caused the problem?

Asked by for the 2005 Kia Amanti
Generally those kind of problems are ignition switch problems. The Electrical switch the key part.