What happened
The aircraft was in cruise flight within clouds at 9,000 feet MSL when it encountered a snow squall. Upon encountering the weather, the pilot attempted to apply carburetor heat to both engines. However, the pilot noted that the carburetor heat control for the left engine was malfunctioning, as it could only be moved one-third of its full travel.
Shortly after this attempt, the left engine lost power. The pilot was unable to maintain altitude and requested vectors to the nearest airport. During the subsequent descent, the right engine also lost power. The pilot then performed a gear-up forced landing in a swampy field.
The investigation
An FAA aviation safety inspector examined the aircraft at the accident site. The inspection revealed that there was water in the cylinders of both engines.