Santa Fe High School was already on edge before today’s mass shooting.

A gunman reportedly opened fire in the southeastern Texas school on Friday morning, killing at least eight people. A suspect has been taken into custody. In a scene now familiar to all Americans, the students were corralled by armed officers outside the building as local TV news helicopters hovered overhead.

But this scene is especially familiar to Santa Fe, because it also happened less than three months ago. On February 28, the school went on lockdown for more than an hour after students and teachers reported hearing “popping sounds” outside.

A sweep of the area found no threat, but it unnerved the school.

“We got behind the teachers desk,” student Jessie Auzton told NBC affiliate KPRC. “I wasn’t scared. Everyone was crying, then I started getting upset.”

Daniel Williams described texting with his daughter Madilyn during the lockdown. “It was nerve-wracking trying to talk to her via text,” he said. “Florida was on my mind. On social media, people were talking about popping sounds, active shooter, you hope your child is OK.”

Williams was referring to the shooting two weeks earlier at Marjory Stoneman Douglas High School in Parkland, Florida, after which the superintendent of Santa Fe schools had written a letter to reassure parents and staff.

“Safety and security has long been and continues to be a priority in our district,” Leigh Wall wrote, noting that the district had seven full-time police officers and five part-timers, “all trained in current nationally standardized protocols to respond to emergency and active shooter situations. All district employees receive annual training and participate in drills routinely throughout the year. The district also actively participates in regular safety, security and intruder assessment audits to ensure safety and preparedness in crisis situations.”

Today showed the limits of such preparedness.