INDIVIDUAL AND OTHER EE WERE ATTEMPTING TO JUMP START TRUCK. HE BEGAN TO WALK ALONG THE FRAME TO CHECK THE CONNECTIONS WHEN HE STOPPED ON THE BATTERY COVER THAT WAS LAYING ON THE FENDER. IT WA S TOO DARK TO SEE WHERE HE WAS STEPPING. HE FELLTO THE GROUND APPROX 4 FT AND HURT HIS RIBS LAYING ON THE GROUND.