DURING HARD BREAKING (ABS ENGAGED) AT 30 MPH CITY TRAFFIC, FOLLOWED BY A FRONT END CRASH, BOTH SEAT BELT RETRACTORS FOR THE TWO FRONT SEAT PASSENGERS FAILED, FAILING TO KEEP THE PASSENGERS SECURED IN THEIR SEATS THE BELTS NEVER LOCKED AND COMPLETELY DESPOOLED. THE DRIVER WAS ABLE TO USE THE STEERING WHEEL TO REMAIN SEATED, HOWEVER THE PASSENGER'S HEAD IMPACTED AND SHATTERED THE WINDSHIELD. THE PASSENGER ALSO HAD BAD BRUISING FROM THE FINAL RESTRAINT OF THE BELTS AFTER IT DESPOOLED AND STOPPED.