why won't anything work when I turn the ignition key?

What is your question?

was driving on freeway. car just died. headlights work, but car won't start. checked the battery, starter, all fuses, everything is fine. when I turn the key nothing lights up on the dash. dash lights work when I turn on the headlights. I have no warning lights or dash lights when I turn on the key. no radio or accessories. can't figure out what happened. can you help me?