Thread by @NBCNews

The moment she heard the first pops of gunfire, the teacher knew what she had to do: She needed to make sure that her classroom door was locked, a seemingly simple task that would require her to take a life-threatening risk. #NBCNewsThreads (1/11) nbcnews.to/3AQYFok

Robb Elementary is among thousands of schools across the country lacking a basic safety feature that experts have recommended for decades: classroom doors that lock from the inside. (2/11)

1 in 4 U.S. public schools lack classroom doors that can be locked from the inside, according to an NCES survey. In 2018, 36% of Texas schools said they did not have interior-locking doors in most of their classrooms. (3/11)

“I was in the hallway with him,” the teacher said of the gunman. Moments after darting back into her classroom, the gunman entered a classroom across the hall — just steps away from where she’d been standing — and opened fire. (4/11)

Both gun rights and gun control groups have all advocated for interior-locking doors since the Columbine shooting in 1999, in which two students killed 12 classmates and one teacher. (5/11)

After the massacre — in which the shooters were only able to access classrooms that were unlocked — schools across the U.S. began installing specialized classroom security locks, sometimes referred to as “Columbine” locks. (6/11)

But the upgrade doesn’t come cheap. Installing a Columbine lock can cost between $200 and $900 per door, according to one industry estimate. (7/11)

The logistics and expense of installing these locks can dissuade districts from investing in them, said Amy Klinger, founder of The Educator’s School Safety Network: “Think about how many schools there are in the U.S. and in each one, you have maybe 200 doors.” (8/11)

For the upcoming school year, Texas will require all districts to conduct weekly checks to ensure their exterior school building doors are closed and locked, and says it is in the process of developing new facility standards. (9/11)

The bipartisan gun control bill that President Biden signed into law last month includes $100M that schools can use for safety infrastructure improvements. Those funds will only go so far, however. (10/11)

The teacher has decided to return to work, but she has one condition. She wants to be able to tell her students that they’re safe, and to really mean it — even if that requires installing a lock herself. (11/11)