The Detroit Public Schools says the district is sending layoff and non-contract renewal notices to all teachers and 248 administrators.
Emergency financial manager Robert Bobb said Thursday the 5,714 notices are a response to the continuing decline in student enrollment.
Bob says the district is determining how many employees will be laid off and that July 29 is the effective date of the teachers' union layoffs.
The district says it's informing salaried workers by letter after May 17 that the contract may change under a new state law giving broader powers to state-appointed financial managers.
Bobb was appointed in 2009 to fix the district's finances. His extended contract is set to expire in June.
Teachers union president Keith Johnson says it's not known how many teachers may be laid off.