My sister had a burst pipe last week, and called me yesterday to ask for help with a flood claim as she was having difficulty filling out the forms. I told her to leave it with me and the first thing I did was call my loss assessor. I was pretty amazed she had no idea what a loss adjuster does!
Basically, he is the guy you should always call first before making an insurance claim, as he will prevent the insurance companies ripping you off.
This video has a lot of information on how a loss assessor can help you in the event you need to make a claim against your home insurance policy.