Science Buddies: "Ask an Expert"

Hi, in new here and not really a scientist.
My boat got hit by lightning. Among the damage was a melted bolt. This bolt holds the cast iron keel to the boat. The bolt is 30mm diameter and approx 20cm long, made of steel. The top of the bolt was completely melted. I am wondering how much power went through it do achieve this? I would like to understand this in a layman's comparison, e.g. To boil a regular kettle for how long? To me this is an awesome charge of energy which I would like to understand. I am asking purely out of curiosity
Thanks
J

Hello,
The Ask the Expert forums are for students in grades K-12 who are doing hands-on science projects. There are other sites on the web where your questions would be more appropriate. Thank you.