When an ex-student opened fire in a Florida school on Thursday, two brothers, both crouching under their desks, texted their goodbyes to one another.
Sam Zeif, 18, was in a class on the floor below 14-year-old Matthew Zeif at Marjory Stoneman Douglas High School in Parkland, when 19-year-old Nikolas Cruz opened fire.
Days after, with 17 of their classmates confirmed dead, their heartbreaking exchange has been revealed.
"Are you okay?" Sam asked his little brother amid the shooting.
"Hopefully," Matthew responded. "Just know, I love you forever and you're the best brother."
"I love you too," Sam replied. "We're gonna get out of here I promise."
Matthew's messages then took an even more distressing turn.
"Are the cops here... my teacher died," he wrote. "And he's sitting in the doorway."
That teacher has since been identified as Scott Beigel, who was unlocking his door to let students hide inside when he was killed.
At that point, Sam said he wasn't sure if police had arrived, and when Matthew stopped responding, frantically sent him a string of messages asking if he was alright.
"Don't DO ANYTHING... you understand?
"Matthew... please answer me.
"Just stay hidden please."
The pair both made it out safely, and the older sibling opened up about the terrifying ordeal later on Twitter.
"Scariest part of it all was knowing my little brother was right above me and not knowing if I would ever see him again," he said.
"I've never really treated him the way he deserved. Not anymore.
"Seeing his face outside of school was the most relief I had ever felt.
"My prayers to all."
After his shooting spree, Cruz visited a McDonald's joint, where he was arrested. He will appear in court charged with 17 counts of murder.