For all the misguided social media chatter about arming teachers with firearms, a more effective deterrent is ensuring school doors are locked. Reports in the wake of the tragedy at Robb Elementary School in Uvalde, Texas, underscore the need for vigilance regarding such mundane policies. The gunman entered through a back door before killing 19 students and two teachers. Texas state police initially reported a teacher propped the door open with a rock while carrying food from a vehicle. It was subsequently revealed the teacher closed the door when she realized the shooter was nearby, but it failed to lock. That points to two problems that are easily addressed. School doors should never be propped open, and they need to function correctly. It\u2019s not that the school lacked security policies. Both exterior and interior classroom doors are supposed to be locked while school is in session. \u201cThere was a regrettable culture of noncompliance by school personnel who frequently propped doors open and deliberately circumvented locks,\u201d the joint committee of the Texas Legislature wrote in a report on the incident. Anyone who works in a school or office building can empathize with how easily such mandates can be compromised. Robb educators are hardly alone in being lax about security measure, but they can offer invaluable lessons for peers across the nation. It\u2019s hardly the only problem revealed in the 77-page report, which was released Sunday. The shorthand was that the school, and emergency personnel, were not prepared for an armed intruder. Every school in America needs accept the reality that it could happen there. The committee determined it would not have been difficult for any intruder to gain access to Robb Elementary. Three exterior doors were unlocked. One of the targeted classroom was routinely accessible due to a faulty latch. There should be no debate over repairing a lock or closing a door at a school. Or to guarantee there are strong mobile connections. The report has drawn more attention for the committee\u2019s rebuke of law enforcement responders. There was no designated commander on the scene, and procedures from active shooting training were not followed. Most damning of all is the personal critique that \u201cthey failed to prioritize saving lives of innocent victims over their own safety.\u201d A jarring 73 minutes passed between the time the gunman entered the school and officers killed him, according to the report. During those minutes, a breakdown in communication led to chaos. Nearly a decade after the massacre in Sandy Hook, Newtown Public Schools Security Director Mark Pompano emphasized the need for active shooting training to be renewed every year. Serendipitously, Newtown staff is scheduled for training in one of the district\u2019s buildings next month. Pompano also stressed that \u201csecurity ... has to start with locking doors.\u201d School officials in Newtown, in Uvalde and in too many other districts know the potential consequences of even a minor security lapse. We all have a responsibility to help close the door on this horrific epidemic of mass shootings.