On June 10, 2007, approximately 0900 mountain daylight time, a Cessna T188C airplane, N2535J, sustained substantial damage as a result of the left main landing gear collapsing during the takeoff roll near Rock Springs, Montana. The certificated commercial pilot, who was the sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the aerial application flight, which was being operated in accordance with 14 CFR Part 137, and a flight plan was not filed. The flight was originating at the time of the accident. In a telephone interview with the NTSB investigator-in-charge (IIIC), the pilot reported that this was the 4th takeoff of the morning, with a chemical load of 170 gallons and full fuel tanks. The pilot stated that after the airplane had progressed about 30 to 35 yards down the runway during the takeoff roll the left landing gear broke, followed by the airplane's left wing hitting the ground. The pilot further stated that the airplane then went up on its nose before coming back down on its right landing gear. The pilot reported that the airplane came to rest in an upright position facing in the direction opposite that of the takeoff roll. In a written statement and in telephone conversations with the IIC, a Federal Aviation Administration airworthiness inspector, who traveled to the accident site, visually inspected the left main landing gear leg and determined that the component failed 6 inches above the wheel.