EE WAS SQUATTING DOWN WHILE FUELING THE LOADER. WHEN HE FINISHED FUELING HE STOOD UP AND WAS COMING DOWN THE STAIRS & LOST HIS FOOTING. AFRAID HE MIGHT HIT THE LOADER HE PUSHED OFF LANDING ON HIS LEFT FOOT THEN SHIFTED HIS WEIGHT TO HIS RIGHT LEG WHEN HE HEARD A POP HE SAT DOWN COULD NOT MOVE HIS LEG WHEN HE TRIED GETTING UP. WHILE THIS WAS HAPPENING IT WAS RAINING HEAVILY.