Symptom: flat tire
Diagnostic: tire damage that requires repair
Most punctures nail holes or cuts up to ¼" confined to the tread may be satisfactorily repaired by trained professional using industry-approved procedures.
Change your flat tire out with your spare tire. Then visit an authorized Michelin tire dealer for an inspection as soon as possible. They can then determine what damage (internally as well as externally) your tire has, and whether to repair or replace your tire.