BARTOW — A report from the National Transportation Safety Board described just how bad the weather conditions were the morning a prominent Polk County lawyer and four others died in a Christmas Eve plane crash.Dense fog cloaked Bartow Municipal Airport on Dec. 24, clouds hung at just 300 feet and visibility was less than a quarter mile, the report said.PREVIOUS COVERAGE: Five dead in Polk County plane crash, deputies say (Dec. 24, 2017)John Shannon, 70, an instrument-rated pilot, was planning to fly to Key West for a holiday lunch. Joining him in the Cessna 340 were his two daughters, Olivia Shannon, 24; and Victoria Shannon Worthington, 26; Victoria’s husband, Peter Worthington Jr., 27; and family friend Krista Clayton, 32.The report is preliminary and did not assign cause. It often takes the NTSB a year or more to complete its investigation and publish a final report.The longtime Lakeland attorney filed an instrument flight plan and received an instrument flight rules clearance from Tampa Air Traffic Control, the report said, though he did not request a weather briefing.Before he took off, Shannon and the passengers piled into the plane while it was in the hangar. Rather than taxi out under the plane’s own power, though, Shannon asked two airport employees to the plane to the ramp."The pilot wanted a tow because he didn’t want to taxi next to the other hangars with the reduced visibility due to the dense fog," the report said.Shannon taxied the rest of the way to Runway 9L. The two airport employees said they heard the Cessna take off, but couldn’t see it through the fog.But shortly after takeoff, they told NTSB investigators, they heard an explosion and drove toward it. They found the plane’s wreckage northeast of the runway, burning.The plane, owned by Aviation Transportation LLC, which state business records show is registered to Shannon, was completely destroyed.Another witness, a helicopter pilot, said he recorded video of the plane taxiing through the fog. He, too, heard the plane takeoff, the report said, then heard a "pop." Three seconds later, the helicopter pilot heard the explosion. He estimated visibility to be between 600 and 800 feet.The report did not indicate how many total flight hours Shannon accumulated, or how many hours he had in a Cessna 340.Contact Josh Solomon at (813) 909-4613 or [email protected] Follow @ByJoshSolomon.