1992 Ford F-250 Engine frozen

I had filled my cooling system with 50/50 Prestone around mid-august and ran it for about 15 miles to get the coolant throughout the system. I have not driven it in 2 months, but was required to move it for the snowplows on 12/22. When I turned it over the engine made a loud squeeling noise so I shut it off to inspect. My belt broke in half so inspected the pulley's and the water pump wouldn't turn. I opened the radiator cap and there was nothing but ice. The lowest it has gotten in my are was 13*F. I have no garage to put my vehicle to warm up the block to check for damage. Any suggestions on how I can fix this and maybe how the anti-freeze froze in the first place.