oil light came on- battery light came on

I too also own a 1999 Chevy Cavalier and I drove it for couple months after replacing the transmission, alternator inside the car. It drove fine completely for month. This year I had to replace the head gasket and water pump too. suddenly while I was driving to work and stop at a red light, the battery and oil light came on at the same time the car died in the middle of the highway. I took it back to the mechanic , he tried cleaning out the engine and did a fuel injection , it still died on me when I stop at the red light. Dont have any idea while it died or what the cause of it ?

when this happened to me it was from my fuel pump going out, it also happened to my mom and it was from a short when she was backing out of her parking space, we both own 2000+ cavaliers