The nation's two largest teachers' unions want schools to revise or eliminate active shooter drills, asserting that they can harm students' mental health and that there are better ways to prepare for the possibility of a school shooting.

The nation's two largest teachers' unions want schools to revise or eliminate active shooter drills, asserting that they can harm students' mental health and that there are better ways to prepare for the possibility of a school shooting. https://t.co/fIR3uTxZGk

— NBC News (@NBCNews) February 15, 2020