Do I owe her any money to help replace the flat iron?

I used friend's flat iron at spa. She asked me to unplug it & I did so. She went home thinking it was 'turned off' and put it where she usually stores it plugged in w/ paddles inbetween rolled up towels. She left apt but came back suddenly & smelled the singed towels. She now feels the flat iron has residue on it and it's not really functioning.