Firebelly toads are called toads because of their bumpy skin but as you accurately have noted they are really frogs.

Frogs absorb chemicals from their environment easily through their skin so first point would be to suspect features of the new tank and its furnishings as possible source of problem. However you mention that only one of the two is showing a change in behavior, which is curious.

Did you scrupulously clean the new rocks before using them. Rinsing and scrubbing with lots of water (avoid using strong soaps or detergents because any residue of that could really be a problem) - even boiling and/or baking them in an oven at below 250° could be a way of making sure they carry no unwanted organisms or substances. Assuming you purchased the rocks to be used with frogs I won't worry about the type of rock (minerals) that they are being exposed to but you may want to think about that also. Anything that would give off a strong salt or other ion element (formerly salt water environment rocks) could affect health.

The new tank must also be prepared and cleaned properly and you need to make sure the water you use for their soaking area has been properly seasoned or filtered to eliminate chlorine.

The aspects of sensitivity of frogs through contact with substances through their skin extends to you also. They can become agitated because of human hand oils and you may experience skin reactions them also (always wash you hands well after touching them). Handling them should be kept to an absolute minimum and use of clean latex or sterile gloves would be recommended.

The fire in your building could put some pretty toxic soup chemicals into the air and that could wind up in the water and surface of their environment so you may want to work carefully to be sure it is very clean.

If you still have their former environment set up I think transferring the listless one back to it to see if there is any change might be a good idea. If you think that your home was contaminated by the smoke then that may not have any real benefit.

Remember they need water area, dry land area and moss to hide in. Temperature is important but higher daytime temps (72°–78°F) and lower nighttime temps (65°F) are normal with a basking area going as high as 75–85°F (very localized, be careful). They need a source of UVB light to facilitate uptake of calcium (full spectrum fluorescent bulbs) but the use of heat lamps for temperature has to be applied carefully.

As you try to revive this listless frog don't go zero to sixty in split seconds, warm the environment slowly so that the return to a more normal range of temperatures is gradual.

Lastly come up with a method to keep their temperature needs more constant if a power outage was to happen again. Using hot water in milk jugs placed around their tank could provide local warmth and even having a plan to relocate the tank to a friend's house where you can set it up for identical conditions to how you have it at home can work.

I hope some of this helps.

Be sure to comment back as the state of your frogs resolves - I am always interested in how these cases resolve.

As a source of more knowledge and expertise I recommend contacting folks through the Pacific Northwest Herpetological Society (PNHS).
Information about their activities and meetings can be reviewed at:
http://www.pnwhs.org/