I plugged in an electric rv water heater and it blew a fuse. What happened and how do I fix it?

Start by unplugging the heater. Install a new fuse or reset the breaker. Shut off the heater and plug it in, nothing should happen. Turn the heater ON, did the new fuse blow?

I forgot to tell you it was plugged into a GFI outlet and that the water heater had no water in it. Can you tell me if I burned up the element in the heater? Is the thermostat fried? What other damage could I have done? The heater seems ok; not melted or burned looking; the fuse popped right away. I checked the fuse box in the camper (old 1976 Road Ranger-no longer made) and reset the breakers. Tested the element and it works. I think the water heater has been replaced within the last 8 years so a newer one. Thanks for the prompt reply and you response. I appreciate all the ideas and help. It is wonderful to find help.

Energizing an electric water heater without water should have burnt out the heating elements within minutes, and could cause a short circuit also.

So what do you have, breakers or fuses, you are saying both terms. What blew or tripped: breaker, fuse or GFCI?