You can feel the horror of the Florida school shooting unfold in this text exchange between two sisters

Updated 8:54 AM ET, Fri February 16, 2018

(CNN)Facing death, 17-year-old Hannah Carbocci wanted her big sister.

A bullet had just pierced the wall of her classroom at Marjory Stoneman Douglas High School in Parkland, Florida. Gunshots -- a lot of them -- had exploded. Someone in her class was hurt. Someone else, somewhere, was yelling.
From under a teacher's desk, Hannah dialed 19-year-old Kaitlin at work.
Nothing.
So, Hannah did what teenagers do. She texted. And Kaitlin pinged back.