Dead Battery? Use a volt meter, the batt at rest should give a reading of a little over 12 volts. Check the cable connections for a clean, tight connection. My wife went into a grocery store, 15 minutes later she came out to find her battery dead, nothing was left on, a battery can die just that fast

Make, model, year and miles are key info to post.

J said, remove negative terminal first then positive, clean them, put back positive then negative. Remove and re-attach in one clean motion.

Check for battery leak, it happens. Check main battery fuse, might be under hood.

Did you hear a pop?

One guess would the ignition switch.

Sounds like a bad connection on the battery. Very common on top post batterys. Simple fix take the connectors off clean the gunk off n then take sand paper n scrub all parts that touch battery n connectors should fire right up.

Bad connection or bad battery, test battery first

you check ignition fuses? might even be a fusible link if your car has one.

What kind of car?

I came home from school at approximately 3:20PM, the car was working perfectly fine, and I left nothing running (no lights, AC, etc.)

Then at 6:30PM, I wanted to go out, but the car would not start. I'll go into every detail. I opened the car, then put the key in the cognition, twisted it, and the speedometers and such lit up for a second. Then everything went dead. No lights, nothing.

I try turning the key again and nothing happens, the emergency lights doesn't work, headlights, and even the power locks won't work.

My dad tried jumping it, didn't work.. We don't know what else is wrong as of right now and we're looking to research. Any tips?

Thanks