Jackie Matthews says she not only survived the Sandy Hook school shooting 10 years ago, but lived through yet another mass shooting - at just 21 years old.

Matthews says she was near the buildings where several people were shot at Michigan State University Monday night.

"I am 21 years old, and this is the second mass shooting I have lived through," said Matthews on TikTok

In a TikTok post, Matthews calls what happened Monday "incomprehensible," sharing that experience triggered PTSD and physical pain from when she had to crouch in her classroom and hide 10 years ago.

Matthews is calling for change, a sentiment shared by one of the founders of Sandy Hook Promise, Mark Barden, whose son Daniel was killed that same day.

"It's just unconscionable that there is a growing segment of our population that are having to endure this more than once, not just Jackie," said Barden.

Adding to the weight of this most recent tragedy, Tuesday marks five years since the deadly shooting at Stoneman Douglas High School in Florida.