Stop in for a cup of coffee

Hmmm so I left the pool party before anyone got too crazy but as I was pulling in at home, I smelled a little smoke and the Fury when I turned the key to off, the engine kept running, finally I jiggled the gear shift and it shut off, popped the hood and fire extinguisher in my hand and I noticed the ground battery terminal was melted off and a little smoke around the battery!! I didn't touch it. What would you do?