The pilot was in the left seat and was getting a check ride from the chief pilot who was in the right seat. After making a series of touch-and-go landings, the aircraft pulled slightly to the left during a takeoff. A full pattern was then flown to runway 17R with the intent of making a full stop landing. Both pilots stated that after a normal touchdown, the aircraft started pulling to the left. They reported that even with full right rudder and full reverse prop, as well as full braking, they were unable to keep the aircraft on the runway. The aircraft departed the left side of the runway and the left main landing gear collapsed. The company maintenance supervisor checked the brakes after arriving at the accident site. He found both left main tires blown out and reported the holes were aligned as though the wheels had not rotated after being locked. He stated the brakes were very hot, but he could rotate the wheels by hand. Investigation did not reveal a malfunction or determine the sequence prior to failure.