On August 13, 2021, about 1555 Alaska daylight time, a Cessna 180 airplane, N3467Y, was substantially damaged when it was involved in an accident at Soldotna Airport (SXQ), Soldotna, Alaska. The flight instructor and the pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that he and the pilot receiving instruction were practicing landings in the tailwheel-equipped airplane. The purpose of the flight was to complete the requirements for a tailwheel endorsement. The pilot receiving instruction had successfully completed a series of touch-and-go landings on runway 25 at SXQ and was conducting another landing. The flight instructor stated that, as the airplane touched down on the paved runway, he heard a “loud thud” just as the pilot receiving instruction applied full takeoff engine power. The airplane began to veer to the left, and the pilot receiving instruction applied full right rudder to correct the veer, but the airplane continued to veer. The flight instructor took control of the airplane, and the pilot receiving instruction stated “we’ve lost the left gear.” The airplane continued off the left side of the runway and entered an area of rough, grass-covered terrain before colliding with a taxiway sign. The airplane’s left main landing gear collapsed, and the airplane came to an abrupt stop next to the runway. The airplane sustained substantial damage to the left wing, fuselage, and empennage. A witness to the accident reported that the right wingtip dragged on the ground as the airplane veered to the left and that the left gear impacted a sign along the taxiway. Another witness reported that the right wing was dragging on the runway for about 200 to 300 ft and that the airplane departed the runway and impacted taxiway lights, which was followed by a gear collapse. A postaccident examination of the runway environment revealed that the airplane touched down about 361 ft from the runway threshold. Ground scars, impact signatures, and tire skid marks on the runway were consistent with simultaneous contact of the right-wing tip and the right main landing gear tire. The airplane continued to veer to the left, for an additional 218 ft from the touchdown point before departing the left side of the runway. The airplane then veered slightly to the right, momentarily reentering the runway surface, but then veered to the left again. The airplane subsequently collided with a taxiway light, a sign, and a runway “wigwag” airfield light system before becoming airborne momentarily again. During the second touchdown, the airplane collided with another runway sign. The airplane wreckage came to rest in an area of rough and uneven grass-covered terrain on the left side of the runway, about 1,249 ft from the initial touchdown point. The right wing had abrasion damage on the wing tip fairing that matched witness marks on the runway. The left main landing gear leg was folded under the fuselage. The entire gearbox structure of the left main landing gear was torn from the fuselage, and the structure remained attached to the upper portion of the spring steel landing gear leg assembly. The airplane examination found no preaccident mechanical anomalies that would have precluded normal operations.