Looks like it was left full of water and froze solid.......
Replacement tanks are available, but you will have to compare what it would cost in labor to exchange the tank versus replacing the entire HWH. I changed the tank in my prior unit to get electric heating added, but if you aren't comfortable doing that work that might cost more to have a repair facility do it than installing a complete new unit.
2014 Seneca 37TS
Toads: 2014 Ford Explorer Sport or 2013 Ford Focus ST