Here is the email of the French Consulate in LA where you obtained your visa
Phone: (310) 235-3257 - Monday through Friday from 2pm to 4:30pm only.
Please note a high number of applicants might prevent us from answering the phone, thus we strongly suggest to contact us via e-mail only
Our contacts
10390 Santa Monica Blvd, suite 410
Los Angeles, CA 90025-6915
Tel: (310) 235-3200 - Fax: (310) 479-4813
Consulate General of France (Offices)
Monday to Friday:8:45am - 6pm
Open to the public (Not Visas)
Monday to Friday: 8:45am - 12:15pm
Tuesday to Thursday : 8:45am - 12:15pm
& 2:00pm - 4:30pm
FOR VISAS, CLICK HERE
Outside of public hours and only in case of EMERGENCY : (310) 625-9713
Hopefully you have copies of your original visa
Send the email now - I would put something like "Visa stolen in Paris - Need replacement" in the subject line
as hard as it might be send the email then carry on with your visit to Paris and await their reply - it is only 2 am in LA so you have a while before anyone will even see your email or you can try and phone.