The pilot said he "landed very smoothly" on runway 19R. During the landing roll the airplane began to pull "very hard to the left." The pilot applied right rudder; however, the airplane continued off of the runway, hit soft dirt, and stopped abruptly. An examination of the airplane revealed that the nose landing gear had collapsed and the left main landing gear tire was flat. Further examination revealed substantial damage to the engine mount, nose trunion, and firewall. The tube in the left main landing gear tire had failed. No other anomalies were reported by the pilot.