In an emotional video on Instagram, Hart said her children attended the school next door to The Covenant School.
After posting the video on Tuesday, Hart said she'd waited a day before posting because it was "too raw".
Hart described helping students of The Covenant School escape the shooter.
"We helped a class of kindergartners across a busy highway that were climbing out of the woods, that were trying to escape the shooter situation at their school," she said.
"We helped all these tiny little ... kids cross the road and get their teachers over there, and we helped a mom reunite with her children."
Hart also said she and her family had moved from Connecticut, where her children attended a school near Sandy Hook Elementary. Sandy Hook was the scene of a 2012 massacre that left 20 children and six adults dead.
"I just don't know what to say anymore. It is just, enough is enough."
View this post on Instagram
Three students and three adults were killed during Monday's shooting in Nashville, and it is the 19th shooting at a school or university in 2023 that has left at least one person injured in the U.S..
Image: Melissa Joan Hart/ Getty
