WHILE WALKING FROM SECURITY BLDG TO GATE EE LOST HIS FOOTING ON WET GROUND, FALLING AND HITTING ON HIS LOWER BACK. HE STATED HE WAS OK, FINISHED HIS SHIFT WORKED THE NEXT DAY. UPON HIS NEXT SC HEDULED SHIFT ON 3/26/00, HE ADVISE HIS DR PUT HIM OUT OF WORK FOR TWO WEEKS.