On July 6, 2001, at 1930 central daylight time, a Piper PA-12 floatplane, N78495, sustained substantial damage when it impacted a tree during a forced landing after a loss of engine power while maneuvering about 700 feet agl. The airline transport rated pilot and one passenger received minor injuries. The 14 CFR Part 91 personal flight departed Surfside Lino-Lakes seaplane base (8Y4), Rice Lake, Minnesota, at 1815, and was en route to Balsam Lake, Wisconsin. Visual meteorological conditions prevailed and no flight plan had been filed. The pilot reported he was climbing out north of Stillwater, Minnesota, and was northbound over the St. Croix River. The pilot reported he, "Made a left bank and engine quit. Leveled wings after losing altitude. Looked and did my engine failure flow and nothing came back. I couldn't make it to the river due to a large tree. I avoided power lines and road and stalled it into some smaller trees and brush. The plane landed upside down. I released my seatbelt and my son's seatbelt and noticed fuel leaking and immediately departed the accident. At point of impact is hard to tell if some power came back." An inspection of the airframe and engine revealed it had 6.5 quarts of oil and residual fuel was found in the carburetor. There was thumb compression on all cylinders and the left magneto sparked on all leads. The exhaust system checked normal and the flame tube was in position and secure. The carburetor inlet was clear and the venturi was is place. The fuel system was compromised. At 1956, the observed weather at St. Paul, Minnesota, located about 17 miles south of the accident, was: winds 170 degrees at 8 knots, sky clear, visibility 10, temperature 84 degrees F, dew point 61 degrees F, altimeter 29.77. According to the Transport Canada "Carburetor Icing Chart", the existing weather conditions were in the region of "Serious Icing-Descent Power."