Brings back some horrid memories. Right after I moved to FL, I had a metal outbuilding built to store all my files, still and cine camera gear, lenses, etc. It was air conditioned/heated at a near constant temp, ideal place to work. One almost stormy day, clouds a swirling to and fro, a thing called a waterspout lifted itself off the Gulf of Mexico and danced its way merrily, merrily as you please up over the coastal houses, alighting neatly on my shed and then promptly danced its way back to the Gulf of Mexico, picking up a '56 Porche on its way and dumped the lot about 200 feet past the first sand bar. Navy divers were kind enough to retrieve both the car and shed, surprisingly with most of the contents, but while the Porche was salvageable, salt water and film cameras, negatives, and everything else after nearly a week in the water...meh, they were only good for the insurance claim.
Yeah, it brings back memories. Sorry for your loss. I do know how it feels.