DENVER A small plane flying from Longmont to Utah lost its left engine before crashing into a mobile home park in Steamboat Springs, according to a preliminary report from the National Transportation Safety Board released Wednesday.The twin-engine Cessna 421 airplane was leaving Vance Brand Airport (LMO) in Longmont and was on its way to Ogden-Hinckley Airport (OGD) in Ogden, Utah, when the pilot reported a cylinder temperature issue and requested to divert to Steamboat Springs Airport/Bob Adams Field (SBS), the preliminary report states.The airplane overflew SBS and requested to divert to Northern Colorado Regional Airport (FNL) in the Fort Collins/Loveland area. While flying towards FNL, the pilot reported to air traffic control that they had just lost the left engine and air traffic control cleared the pilot back to SBS for landing.While doing a final turn toward a runway at SBS, the airplane was observed by witnesses to enter a flat, spiraling descent and impact terrain, according to the report, which then states that a post impact fire ensued and consumed a majority of the airplane.The plane crashed into West Acres Mobile Home Park in Steamboat Springs, killing 67-year-old Dan Dunn and 42-year-old Jessica Pauline Melton.The crash caused a fire that spread to two trailers at the mobile home park, but none of its residents were injured.The preliminary report states that the impact occurred 0.4 miles from the approach end of a runway at SBS.At the scene of the crash, NTSB investigators found that the propeller blades on the left engine appeared to be in the feathered position, with most of the cockpit instrumentation and avionics devices consumed by the post impact fire.The NTSB said a final report could take up to two years as they look into the pilot, the plane and the operating environment. Plane lost left engine before crashing in Steamboat Springs: Prelim. NTSB report