“The shooter was struggling with his weapon at this time,” Fitzpatrick said. The gun appeared to be jammed, and he was having trouble loading ammunition, Fitzpatrick said.

The superintendent believes that interaction gave staff a few more seconds to get children into classrooms, completing the lockdown.

Surveillance video shows that between eight to 10 seconds after every room was secured, the shooter entered the quad, Fitzpatrick said.

“The school secretary recognizing the threat — that quickly made all the difference between 100 kids being around today and dozens being shot or killed,” he said. “That amount of seconds was critical.”