Los Angeles-area West Harvard-Westlake High School closed after former Miami Dolphins lineman Jonathan Martin posted a photo of pump shotgun on Instagram.

He put the hashtag #HarvardWestlake on the side of the gun.

12 Up’s Nick Brown tweeted a photo of the Instagram post, which showed Martin had captioned the photo by writing, “When you’re a bully victim and a coward, your options are suicide, or revenge:”

Former Dolphins OL Jonathan Martin with some seriously disturbing stuff on his IG story… pic.twitter.com/NaJ8a0BXze — Nick Brown (@NickyBeaster) February 23, 2018

The New York Post reports that Martin posted the photo one week after Nikolas Cruz opened fire on Marjory Stoneman Douglas High School, killing 17. Harvard-Westlake reacted to the post by announcing a school closure on both of its campuses: “Last evening, we learned of an Internet post that mentions Harvard-Westlake by name. Out of an abundance of caution, and because the safety of our students, faculty, and staff is our top priority, we made the decision to close school today. We are working closely with law enforcement and will share more information when we are able.”

Martin retired from the NFL in 2015.

AWR Hawkins is an award-winning Second Amendment columnist for Breitbart News, the host of the Breitbart podcast Bullets with AWR Hawkins, and the writer/curator of Down Range with AWR Hawkins, a weekly newsletter focused on all things Second Amendment, also for Breitbart News. He is the political analyst for Armed American Radio. Follow him on Twitter: @AWRHawkins. Reach him directly at awrhawkins@breitbart.com. Sign up to get Down Range at breitbart.com/downrange.