Keep calm and (try to) carry on.
Call your local embassy to begin the process of obtaining a new one and bring identification such as a driver’s license and a photocopy of your passport and visa (if applicable).
Call ISOS for advice. ISOS cannot set up an appointment or replace your passport but can give you advice and support. They will direct you to a nearby embassy or consulate to obtain a new one.
Let your MISTI program manager know so they may provide assistance.
MIT will notify the International Students Office if your passport with its US re-entry visa is lost.
Calle de Serrano, 75
28006 Madrid, Spain
Phone: (+34) 91-587-2200
Fax: (+34) 91-587-2303
US Consulate
Paseo Reina Elisenda de Montcada, 23
08034 Barcelona, España
Phone: (+34) 93 280 22 27
Webpage