Dennis Walcott made changes to the city public school field trip policy Thursday, nearly a year after a student's death.
The Education Department's list of teacher layoffs would cut as much as 70 percent of teaching staff at some schools.
Principal Jose Maldonado-Rivera was removed Tuesday for alleged financial misconduct involving a girlfriend.
Former Columbia Secondary School teacher Erin Bailey will not face criminal charges in the 12-year-old's death.
Nicole Suriel drowned during a poorly-supervised school field trip to Long Beach in June.
Assistant principal Andrew Stillman chose an unguarded beach for a school trip, at which Nicole Suriel drowned.
Teachers at Columbia Secondary School are angry at the punishment given to the school's principal after a student drowned.
The teacher who let kids she knew couldn't swim into the water, leading to a girl's drowning, was fired.
Police have launched a crime probe after claims 12-year-old Nicole Suriel was allowed in the water.
Friday would have been the last day of sixth grade for Nicole Suriel, who drowned during a school trip this week.