THE EE WAS WORKING ON A VENT BAG WHEN THE PIECE OF ROPE HE WAS USING GAVE WAY AND HE LOST HIS ALANCE AND FELL BACKWARD. HE PUT HIS FOOT OUT TO CATCH HIMSELF AND TRIPPED ON A VENT BAG THAT WAS ROLLED UP BEHIND HIM. HE STRUCK THE BACK OF HIS HEAD ON A METAL BOX. HE WAS TRANSPORTED TO E.R. FOR EVALUATION AND TREATMENT.