Your insurance company will be interested in the so-called heavy duty quonset hut, the specifications, the materials that came with it and what they say, and what representations were made by the seller. Two feet of wet snow is heavier than 10 lbs/sq. ft., but such snow is to be expected in Connecticut. It may not happen often, but it does happen periodically. I hope you informed the insurer of the quonset hut so it is covered on your homeowners' policy (and I hope you have homeowners' insurance). The insurance on the RV's may also have some coverage. If you have no insurance, you can make a claim against the vendor that sold you the quonset hut. Start reading whatever information came with the cover and go to the vendor and see what they claim about the products they sell.
Snow is to be expected. The cause of the collapse may be the cover's not so heavy duty construction.