AFTER A STABILIZED APCH IN A SLIGHT CROSSWIND A C172 WAS PUSHED TO THE LT RWY EDGE BY A GUST STRIKING A RWY LIGHT; COLLAPSING A GEAR AND DEPARTING THE RWY.

Narrative

I WAS ON A XCOUNTRY FLT FROM ZZZ TO ZZZ1 TO SATISFY PART OF THE REQUIREMENTS FOR A COMMERCIAL CERTIFICATE. THE TWR CLRED ME TO LAND ON RWY 17 AND I PROCEEDED TO TURN ONTO A 3 MI FINAL. I FLEW THE APCH KEEPING THE AIRSPD BTWN 65-68 KTS. I WAS ESTABLISHED IN A STABILIZED CONFIGN WITH FLAPS AT 30 DEGS ON AN EXTENDED CTRLINE APCH IN VFR CONDITIONS. THE WINDS WERE BTWN 150-160 DEGS AROUND 13-15 KTS. I HAD THE AIRPLANE SET UP TO TOUCH DOWN BTWN THE NUMBERS AND THE THOUSAND FT BLOCKS. I HELD A VERY MINIMUM AMOUNT OF L RUDDER TO REMAIN ON THE ESTABLISHED APCH. ONCE I FLARED FOR LNDG; THE AIRPLANE TOUCHED DOWN AS THE STALL WARNING HORN BEGAN TO SOUND. JUST AFTER TOUCHDOWN; THE AIRPLANE VEERED TO THE L; CAUSED BY WHAT I BELIEVE TO HAVE BEEN A GUST OF WIND FROM THE R. THE L MAIN THEN CAME OFF THE GND. I ADDED L AILERON AND GOT THE GEAR DOWN. AT THIS POINT; I WAS OVER THE L RWY EDGE MARKING AND BEGAN TO ADD BRAKING AND LIGHT R RUDDER TO TRY AND MANEUVER THE PLANE BACK TO THE MIDDLE OF THE RWY. THE AIRPLANE THEN STRAIGHTENED OUT HEADED DOWN THE SIDE OF THE RWY WHEN THE L MAIN GEAR STRUCK A TXWY SIGN. THE AIRPLANE THEN STARTED TURNING L INTO THE GRASS AND THE L MAIN GEAR BEGAN TO COLLAPSE. AS THIS WAS HAPPENING; I REACHED OVER AND PULLED THE MIXTURE OFF AND SHUT DOWN THE ENG. THE AIRPLANE CAME TO REST IN THE GRASS L OF RWY 17; APPROX 3500 FT FROM THE APCH END.