You will need to explain what happened to USCIS in a written response. You need to submit this request within the timeframe provided by the immigration officer. Did you file a police report or notify your consulate of the lost passport? Do you have a copy of your passport? Did you apply for a new passport yet? If so, submit this evidence with the response. If not, you should contact the police and/or your consulate immediately.
Answered on Sep 24th, 2015 at 4:31 PM