People lose their I.D. all the time...and the airlines cope with it. they will accept alternative I.d. like S.S. card. credit cards. See site below...he will be ok...they may put him through an extra security check, but it will be ok. Tons of people have this problem and the airlines manage to help them.
yes, he must go to airline front desk at least 2 hr before departure and have some identification ready( such as birth certification , passport ,school ID, temporary license, old license copy...) to get a sticker passing though security check
Read this article: towards the bottom it talks about what happens if you lose your ID in the US. The first part is talking about if you are out of the country.http://www.fodors.com/news/story_928.htm��