(CNN) Carly Novell survived the shooting rampage at Marjory Stoneman Douglas High School in Florida by hiding in a closet -- and her grandfather also escaped a lone gunman the same way almost 70 years ago.

The 17-year-old senior tweeted on Thursday about her being the second member in her family to survive a mass shooting.

This is my grandpa. When he was 12 years old, he hid in a closet while his family was murdered during the first mass shooting in America. Almost 70 years later, I also hid in a closet from a murderer. These events shouldn't be repetitive. Something has to change. #douglasstrong pic.twitter.com/nDctTNlUNs — carly (@car_nove) February 15, 2018

"This is my grandpa. When he was 12 years old, he hid in a closet while his family was murdered during the first mass shooting in America. Almost 70 years later, I also hid in a closet from a murderer. These events shouldn't be repetitive. Something has to change," Novell tweeted.

Her grandfather, Charles Cohen, survived a mass shooting by a lone gunman, who was considered to be the first single-episode mass murderer in American history.

In an interview with CNN's Don Lemon on "CNN Tonight," Novell's mother, Merri Novell, said she was always wary of school shootings.

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