Julian Moreno was in his front yard watering his plants when he heard rapid, loud booms on the morning of May 24. At first, he thought it was noise from nearby construction. But people began screaming and running toward Robb Elementary School, a block away from his home. He immediately dropped his hose and made his way toward the gunshots as quickly as his 82-year-old body could take him.

“I knew Lexi was in there,” he tells TIME, his voice breaking and his face quivering.