What would cause my 92 honda accord ex to suddenly shut off and then not start again while I was idiling?

Just the other night I pulled up and parked in front of my place the engine was running as I was looking for something in the the glove box and then the engine just shut off… I tried starting it again and it would not start. The next morning I went out it started right up ran for 15 seconds then it shut off and has not started again… This car has always started up like a champ and I have never had trouble with it idling and shutting off before…
3 weeks ago I had the oz sensor replaced.Wondering if that could have anything to do with the current problem… Hoping it is not the fuel pump. Since I've had the car I was told that if I kept the gas tank above half a tank that my fuel pump should never be a problem… Also when I try to start the car and pump the pedal you can smell gas… Just trying to give you as much info as I can that might help… Any sound advice would be Greatly Appreciated!

The symptoms you've described fit the main relay or ignition switch failures but also the ICM. These links may help, do some reading to identify which would be the cause:
http://easyautodiagnostics.com/honda_dist_ignition/honda_ignition_systems_1.php
http://www.tegger.com/hondafaq/mainrelayoperation/index.html
http://techauto.awardspace.com/ignitionswitch.html

Look at this answer I have given to another member for the same problem/concern:

Hope I have given to you enough information to make the Accord run again. E mail if you need more help.

Could be a bunch of different things. Have you got spark? Test the fuel pump pressure. Check the timing belt marks so you know if the timing belt jumped. Hold the gas pedal top the floor if you think the motor is flooded. The main relay under the steering wheel column goes bad.

The fuel tank is empty.