On July 9, 2017, about 1220 Alaska daylight time, a float-equipped Cessna 180 airplane, N2429C, was substantially damaged when it was involved in an accident in Anchorage, Alaska. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that the airplane's annual inspection was completed the previous week and that the accident flight was the first flight after its return to service. He hadn’t flown the airplane in about 9 months, and the purpose of the accident flight was to perform takeoffs and landings at a nearby lake. Before the flight, he fueled the airplane to capacity, checked the fuel for contaminants, and noted no abnormalities. After takeoff from the north water lane at Lake Hood Seaplane Base (LHD), and during climb out, he was unable to move the flap handle and retract the airplane’s wing flaps. He maneuvered the airplane to a right downwind to return for landing, and soon thereafter, at an altitude of 600 ft and an airspeed of 70 knots, the engine lost total power. He lowered the nose to attain glide speed and initiated a forced landing to an open field. When he realized that the airplane would not reach the intended landing site, he aimed for an adjacent residential road. The airplane collided with a 40-ft-tall tree, a light pole, two houses, and a vehicle before impacting the road. A witness in the area at the time of the accident reported hearing the engine change from normal rpm to silence, and then she heard a loud ground impact. The airplane came to rest upright with both floats bent under and to the left of the fuselage. The right wing leading edge exhibited a large impact indentation that corresponded to the fallen light pole. The wings, fuselage, engine firewall, and empennage sustained substantial damage. There was evidence of fuel spillage at the site from the ruptured fuel lines at the wing roots. A fuel sample exhibited a clear, blue color and was free of contaminants. The pilot stated that he turned the fuel selector from "both" to "off" after the accident. All major components of the airplane were located at the scene. Flight control continuity was established from the cockpit to the control surfaces. The aileron interconnect balance cable was fractured near the right door post with broomstraw signatures. The flap handle was in the 20° detent and was easily moved through all the detents with corresponding cable movement. The right wing flap cable was separated at the wing root with broomstraw overload signatures. A headset cord from the right seat was wrapped around the flap handle base. Fuel was present in the header tank and gascolator. The fuel selector valve was functionally tested in all positions and the fuel lines from the wing roots to the gascolator were clear of obstructions. The fuel line from the fuel flow transducer to the fuel manifold valve contained no fuel and the manifold contained only residual fuel. The engine was test run at various power settings and the throttle was rapidly moved from idle to full power multiple times with no discrepancies noted. The postaccident examinations of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. A review of the maintenance logbooks revealed that the last documented annual inspection was in 2013; the pilot and a mechanic stated that the inspection completed the week before the accident was not yet annotated in the logbooks.