She has a special hatred of seeing her friends on fire, so she is going to deal with those flames in short order. (She really needs to stop making friends with people who come home on fire. This is going on her to-do list.)

Then she kneels down next to him, looking him over more carefully this time. This buys her a little time to process what he's saying. His whole world is gone? Is that why he couldn't get home? She just manages to put the extinguisher down before she drops it.

"I'm so sorry." She holds out a hand to him. Now is not the time to upset him further with assumptions gone amiss. "Oh, Naugus, I'm sorry."