What might be wrong w/ my car if you hear a screeching sounds when you turn key on 1999 Saturn SC2

The car doesn't turn over but just makes an awful noise. Lights come on but won't start.

Asked by for the 1999 Saturn SC2
hopefully its just your starter but it might be your fly wheel has broken teeth
thank you for the response. regarding the flywheel having broken teeth... how might something like that happen?
if someone turns the starter over while engine is running