Three students who survived the Florida school massacre joined about 2,500 other Jewish teens for an annual Chabad youth summit in Brooklyn on Sunday — prompting everyone there to make mitzvah pledges in memory of those killed.

Maverick Reynolds, a 15-year-old freshman from Marjory Stoneman Douglas HS, said the summit was “really important” for his healing.

“It helps me see that everybody actually cares and wants to help out,’’ the teen said. “It’s nice to see how everyone is like sticking together and being stronger together after the experience.”

Another freshman who survived the school shooting, Christopher Branum, said he was honored to attend the Brooklyn event.

“We will not let this [violence] stand,” the 15-year-old said. “I’m proud to be apart of this” summit.

Lauren Berg, 14, who attends a different Florida high school but was a friend of slain Stoneman Douglas student Gina Montalto, said, “I’m going to light some candles for my friend Gina, and I’m going to make challah [bread] every week.”

The 10th annual Chabad Teen International CTeen meeting was held at the Brooklyn Cruise Terminal.

Rabbi Shaya Denburg, director of CTeen in Coral Springs, Fla., brought a group from the state to the convention for the first time this year.

“Now it’s not about going to New York for a weekend; it’s about going to a place with other kids their age who will support and encourage them, and hopefully, provide strength to move forward,” the rabbi told Chabad.org.

Cruz is accused of opening fire on his former campus earlier this month, killing 17 students and teachers.